PubAnnotation

Id	Subject	Object	Predicate	Lexical cue
T1	1568-1620	Epistemic_statement	denotes	To interpret skin biopsies, pathologists must have a
T2	1621-1706	Epistemic_statement	denotes	We gratefully acknowledge the contributions to prior editions of this chapter by Drs.
T3	2387-2487	Epistemic_statement	denotes	In addition to causing undo suffering, severe skin disease may interfere with the human-animal bond.
T4	2644-2795	Epistemic_statement	denotes	The protective barrier of the skin is complex, and much of this function is provided by the stratum corneum (SC), the outermost layer of the epidermis.
T5	3058-3160	Epistemic_statement	denotes	They have a complex structure that includes cadherin proteins of 2 types-desmocollins and desmogleins.
T6	3909-4019	Epistemic_statement	denotes	This layer is much thicker in nonhaired skin and may be up to 20 cells thick in the footpads and nasal planum.
T7	4020-4134	Epistemic_statement	denotes	• The stratum granulosum is variably apparent on light microscopy in haired skin and appears only 1-2 cells thick.
T8	5298-5429	Epistemic_statement	denotes	In doing so, keratinocytes must lose a large amount of water volume (from 70% water in nucleated layers to 15% in stratum corneum).
T9	5430-5565	Epistemic_statement	denotes	Minor injuries to the corneal layer from tape stripping or applications of solvents will result in increased transepidermal water loss.
T10	5566-5828	Epistemic_statement	denotes	Several steps must occur for cornification to proceed normally: (1) bundling of keratin to establish the corneocyte core, (2) replacement of the cell membrane with a thick cornified envelope, (3) formation of lipid lamellar bilayers, and (4) active desquamation.
T11	5829-5930	Epistemic_statement	denotes	Alterations in any step can lead to hyperkeratosis, clinical scaling, and decreased barrier function.
T12	6581-6806	Epistemic_statement	denotes	Although the architecture of the skin is conserved across most mammalian species, the pathologist must be aware of differences between species and site differences within the same species, to interpret normal versus abnormal.
T13	9039-9153	Epistemic_statement	denotes	Commitment to differentiation in suprabasal keratinocytes is associated with induction of keratins 1 (K1) and K10.
T14	10883-11043	Epistemic_statement	denotes	There has been a long-standing debate over whether Merkel cells originate from epidermal or neural stem cells, but current studies indicate an epidermal origin.
T15	11663-11856	Epistemic_statement	denotes	Merkel cells form Merkel cell-neurite complexes with axons in tylotrich pads and sinus hairs that are thought to function as gentle touch receptors that initiate slow-adapting type 1 responses.
T16	11857-12051	Epistemic_statement	denotes	Their exact function in these structures is uncertain, but they are thought not to act as sensory cells but rather to function as abutments for deformation of the mechanosensitive nerve endings.
T17	12052-12169	Epistemic_statement	denotes	Merkel cells are also thought to have various neuroendocrine effects and to be involved in control of the hair cycle.
T18	12170-12291	Epistemic_statement	denotes	The basement membrane zone (BMZ) is the structurally and biochemically complex junction between the epidermis and dermis.
T19	12846-13001	Epistemic_statement	denotes	The BMZ has a crucial role in anchoring the epidermis to the dermis, and abnormalities of the BMZ result in serious and potentially fatal bullous diseases.
T20	13002-13160	Epistemic_statement	denotes	The BMZ also influences growth and differentiation of keratinocytes and acts as a selective barrier for passage of molecules between the epidermis and dermis.
T21	14855-15093	Epistemic_statement	denotes	Melanocytes are located in the basal layer of the epidermis and outer root sheath of hair follicles; and in hematoxylin and eosin (H&E) sections, they appear as clear cells with a small dark-staining nucleus because of shrinkage artifact.
T22	15141-15196	Epistemic_statement	denotes	The dendritic processes can be seen with silver stains.
T23	15719-15848	Epistemic_statement	denotes	Most melanin pigment in skin is in the basal layer, but in dark-skinned animals, melanin may be present throughout the epidermis.
T24	16407-16574	Epistemic_statement	denotes	They appear as clear cells on routine H&E sections and may be distributed from the stratum basale to the stratum spinosum, depending on species and region of the skin.
T25	16575-16632	Epistemic_statement	denotes	They are usually less numerous than melanocytes, however.
T26	17170-17344	Epistemic_statement	denotes	The ground substance is usually not visible in normal H&E sections; however, a fine granular to fibrillar basophilic material is occasionally evident between collagen fibers.
T27	18250-18352	Epistemic_statement	denotes	The skin is supplied with sensory and autonomic nerves that are usually associated with blood vessels.
T28	20142-20270	Epistemic_statement	denotes	SCF is thought to home mast cells to the dermis as well as regulate the synthesis of mast cell mediators and secretory function.
T29	20608-20920	Epistemic_statement	denotes	Degranulation of both canine and human mast cells is thought to involve breakdown of their secretory granules located on the basal aspect of basal keratinocytes, and they consist of a cytoplasmic plaque that connects to the cytoskeleton and a transmembrane portion that binds to the underlying basement membrane.
T30	24305-24484	Epistemic_statement	denotes	Fibronectins are glycopro-has been suggested as a more appropriate term to encompass the skin-specific immune response-associated cells and humoral factors present in normal skin.
T31	24819-24972	Epistemic_statement	denotes	• Langerhans cells are thought to trap antigens in the epidermis, migrate out to regional lymph nodes via lymphatics, and present the antigen to T cells.
T32	25636-25840	Epistemic_statement	denotes	• E-selectin is thought to act as an adhesion molecule or vascular addressin for a specific subset of skin-homing memory T cells, which have the ligand cutaneous lymphocyte antigen (CLA) on their surface.
T33	25983-26241	Epistemic_statement	denotes	Thus it appears that the proinflammatory, upregulating effects of keratinocytes prepare the dermis for specific immunologic activity, whereas migrating antigen-presenting Langerhans cells induce expansion of specific lymphocytes in skin-draining lymph nodes.
T34	26609-26737	Epistemic_statement	denotes	In general, however, hair follicle density is greatest over the dorsolateral aspect of the body and least on the ventral aspect.
T35	26817-26995	Epistemic_statement	denotes	Primary hairs have a large diameter, are rooted more deeply in the dermis or subcutis, and are associated with sebaceous and epitrichial sweat glands and an arrector pili muscle.
T36	26996-27169	Epistemic_statement	denotes	Secondary hair follicles are smaller in diameter, are more superficially rooted, and may be accompanied by a sebaceous gland but lack a sweat gland and arrector pili muscle.
T37	28341-28576	Epistemic_statement	denotes	A subpopulation of mast cells that does not exhibit metachromasia following formalin fixation has been demonstrated in the skin of dogs and cattle, and heterogeneity of protein content has been identified in dermal mast cells of sheep.
T38	29123-29413	Epistemic_statement	denotes	Mast cells also function in persistent chronic inflammatory reactions, tissue repair and remodeling, pathologic fibrosis, angiogenesis, hemostasis, hematopoiesis, antibody production, protection against bacterial infections, response to neoplasms, and possibly in control of the hair cycle.
T39	29901-29991	Epistemic_statement	denotes	Contraction of arrector pili muscles may also be involved in emptying of sebaceous glands.
T40	30075-30138	Epistemic_statement	denotes	They may be vacuolated in normal animals, especially aged dogs.
T41	30429-30485	Epistemic_statement	denotes	The functional significance of this muscle is uncertain.
T42	30486-30572	Epistemic_statement	denotes	Skeletal muscles may be present in the muzzle, forehead, eyelid, and perianal regions.
T43	30705-30787	Epistemic_statement	denotes	Skeletal muscle fibers also are associated with the large sinus hairs of the face.
T44	30788-31120	Epistemic_statement	denotes	The skin has been proposed to function as an immunosurveillance organ, and the term skin-associated lymphoid tissue (SALT), analogous to gut-associated and bronchial-associated lymphoid tissues (GALT, BALT) , has been suggested to describe those cellular elements of the skin that deal with antigenic challenges at the skin surface.
T45	31121-31269	Epistemic_statement	denotes	However, this concept has been disputed because of presumed differences in immune function between the common mucosal immune system and normal skin.
T46	31270-31410	Epistemic_statement	denotes	The alternative name, skin immune system (SIS), activity is thought to be an adaptive response to seasonal variation in ambient temperature.
T47	31647-31728	Epistemic_statement	denotes	The hair cycle in the remaining follicles could not be assigned a specific stage.
T48	33142-33388	Epistemic_statement	denotes	In rodents, the bulge region of the follicle appears to be the site that contains slowcycling relatively undifferentiated cells from which arise a population of transient amplifying cells that become the matrix keratinocytes of the new hair bulb.
T49	33678-33831	Epistemic_statement	denotes	Hair growth in many animals has been shown to be regulated by photoperiod, ambient temperature, various hormones, nutritional status, and general health.
T50	33832-33913	Epistemic_statement	denotes	However, the exact mechanisms that control the cycle are incompletely understood.
T51	34327-34467	Epistemic_statement	denotes	Factors from the papilla mesenchymal cells are thought to act on a stem cell population in the permanent upper portion of the hair follicle.
T52	34608-34763	Epistemic_statement	denotes	Transition between anagen and catagen appears to be regulated by The histologic appearance of the hair follicle changes considerably during the hair cycle.
T53	35233-35334	Epistemic_statement	denotes	Goats have primary follicles in groups of 3, with 3-6 secondary follicles associated with each group.
T54	35539-35603	Epistemic_statement	denotes	As many as 15 hairs may emerge from a single follicular orifice.
T55	36283-36857	Epistemic_statement	denotes	In longitudinal section, the fully developed hair follicle consists of 3 segments: • The lower or inferior portion, from the base of the follicle to the point of insertion of the arrector pili muscle • The isthmus, the short section from the attachment of the arrector pili muscle to the entrance of the sebaceous duct • The infundibulum, extending from the entrance of the sebaceous duct to the follicular orifice The inferior segment can be considered temporary because it disappears during the involution stage of the hair cycle and reforms again during the active phase.
T56	39326-39483	Epistemic_statement	denotes	They are usually largest in areas with lowest hair follicle density, such as mucocutaneous junctions, interdigital spaces, coronet, and dorsal neck and rump.
T57	39731-39875	Epistemic_statement	denotes	The footpads and nasal planum are devoid of sebaceous glands, and they are rare in glabrous skin, where they empty directly to the skin surface.
T58	40162-40307	Epistemic_statement	denotes	The anal sacs are squamous epithelial-lined cystic cavities containing odoriferous secretions, presumably with some territorial marking function.
T59	41031-41114	Epistemic_statement	denotes	Larger ducts, lined by stratified squamous epithelium, may be evident in neoplasms.
T60	41115-41221	Epistemic_statement	denotes	These ducts are thought to regress during embryonal development, which leaves the glands largely ductless.
T61	41309-41442	Epistemic_statement	denotes	Their function is uncertain, but they may have a role in steroid metabolism, in production of pheromones, and in territorial marking.
T62	41585-41722	Epistemic_statement	denotes	Two types of sweat glands are present in the skin of mammals; they differ in origin, distribution, and possibly in the mode of secretion.
T63	41723-41982	Epistemic_statement	denotes	These glands have been called apocrine and eccrine glands, but because of questions concerning the mechanism of the secretory process of these glands, the names epitrichial and atrichial glands have been proposed for apocrine and eccrine glands, respectively.
T64	42158-42459	Epistemic_statement	denotes	Epitrichial glands are associated with primary hair follicles only, and they tend to be largest in areas with lower hair follicle density, such as mucocutaneous junctions, interdigital follicles have a well-developed, flame-shaped, plump dermal papilla (DP) that is capped completely by the hair bulb.
T65	42688-42867	Epistemic_statement	denotes	Catagen, the intermediate remodeling stage, is short-lived and very difficult to assess on routine histology as it requires a perfectly sectioned follicle in a longitudinal plane.
T66	43432-43617	Epistemic_statement	denotes	Telogen may be further described as "haired telogen," which has retention of the hair shaft, and "hairless telogen" or "kenogen," in which a telogen follicle rests without a hair shaft.
T67	45334-45511	Epistemic_statement	denotes	Sebaceous glands also appear to be involved with normal hair development, because, in the absence of sebaceous glands, the hair shaft fails to separate normally from the sheath.
T68	46173-46270	Epistemic_statement	denotes	In other species, the secretion may contribute to scent that is involved in social communication.
T69	46271-46413	Epistemic_statement	denotes	Epitrichial secretion may also provide a means of excreting waste products and secreting immunoglobulins that are present on the skin surface.
T70	46711-46841	Epistemic_statement	denotes	The duct empties into the pilary canal, usually above the entrance of the sebaceous duct or, rarely, directly to the skin surface.
T71	46842-46983	Epistemic_statement	denotes	The name apocrine refers to the mode of secretion, which was originally thought to involve pinching off (apo = off) of a portion of the cell.
T72	46984-47223	Epistemic_statement	denotes	The existence of an apocrine secretory process has been questioned; however, ultrastructural examination of these glands in humans, pigs, horses, and dogs indicates that several modes of secretion are involved, including the apocrine type.
T73	47586-47630	Epistemic_statement	denotes	The function of eccrine glands is uncertain.
T74	47631-47757	Epistemic_statement	denotes	The secretion may be involved with scent signaling, and in the footpad of cats, it may improve frictional capacity of the paw.
T75	48285-48310	Epistemic_statement	denotes	granulomas may be formed.
T76	48311-48461	Epistemic_statement	denotes	Flame figures may be seen in eosinophilic granuloma, insect-/arthropod-bite reactions, and other eosinophil-rich conditions, such as mast cell tumors.
T77	48835-49013	Epistemic_statement	denotes	Crusts should be examined closely for dermatophyte spores and hyphae, Dermatophilus congolensis, and acantholytic keratinocytes, which can be indicators of superficial pemphigus.
T78	49249-49399	Epistemic_statement	denotes	The dilated lymphatics and widened perivascular and interstitial spaces may or may not contain lightly eosinophilic, homogeneous, proteinaceous fluid.
T79	49465-49700	Epistemic_statement	denotes	Severe edema of the superficial dermis may result in subepidermal vesicles and bullae, necrosis of the overlying epidermis, and predisposition to artifactual dermoepidermal separation during handling and processing of biopsy specimens.
T80	49701-49887	Epistemic_statement	denotes	Severe edema of the superficial dermis may result in vertical orientation and stretching of collagen fibers, producing the "gossamer" (web-like) collagen effect seen in severe urticaria.
T81	50214-50348	Epistemic_statement	denotes	Dyskeratosis may be seen in a number of dermatoses, including lupus erythematosus, erythema multiforme, and graft-versus-host disease.
T82	50349-50415	Epistemic_statement	denotes	It can also occur in neoplastic dermatoses, especially papillomas.
T83	50655-50755	Epistemic_statement	denotes	It is an abnormal but nonneoplastic change; however, it can accompany or precede neoplastic changes.
T84	50912-51112	Epistemic_statement	denotes	Dystrophic mineralization of the hair follicle basement membrane can be seen in hyperglucocorticism, in dogs receiving exogenous glucocorticoids, and as a senile change in dogs, especially in Poodles.
T85	51206-51496	Epistemic_statement	denotes	They are found within the epidermis as well as the hair follicle outer root sheath, and are most commonly found in diseases associated with tissue eosinophilia, such as feline eosinophilic plaque and feline eosinophilic granuloma, and thus are associated with allergic skin disease in cats.
T86	51703-51960	Epistemic_statement	denotes	Exocytosis of neutrophils implies an infectious process, whereas exocytosis of eosinophils suggests a hypersensitivity reaction, such as ectoparasitism and feline Dermal atrophy is thinning of dermal collagen fibrils resulting in decreased dermal thickness.
T87	52423-52500	Epistemic_statement	denotes	Clefts may be caused by acantholysis or hydropic degeneration of basal cells.
T88	52501-52562	Epistemic_statement	denotes	However, clefts may also result from handling artifacts (Fig.
T89	53214-53316	Epistemic_statement	denotes	Festoons can be seen in mechanobullous disorders, such as epidermolysis bullosa or bullous pemphigoid.
T90	53481-53605	Epistemic_statement	denotes	The fibrinoid change results in loss of structural detail and may be accompanied by necrotic cell debris or leukocytoclasia.
T91	53859-54035	Epistemic_statement	denotes	These can be seen in endocrinopathies, hair cycle arrest, and are also prominent in normal haired skin of plush-coated breeds of dog, such as the Nordic breeds and Pomeranians.
T92	54473-54572	Epistemic_statement	denotes	It can further be divided into mural folliculitis (inflammation of the follicular epithelium) (Fig.
T93	54956-55097	Epistemic_statement	denotes	This can be seen in any process that is destructive to hair follicles, such as bacterial infection, dermatophytosis, demodicosis, and trauma.
T94	56067-56226	Epistemic_statement	denotes	By definition, hamartomas are congenital lesions; however, they may not be detected until later in life, and the term is often used interchangeably with nevus.
T95	56372-56528	Epistemic_statement	denotes	Hamartoma is the term preferred in veterinary dermatopathology; however, there are a few conditions where "nevus" is ingrained in the veterinary literature.
T96	57673-57759	Epistemic_statement	denotes	Hypergranulosis may be seen in any dermatosis in which there is epidermal hyperplasia.
T97	57829-57921	Epistemic_statement	denotes	It can be either orthokeratotic (without nuclei) , or parakeratotic (nuclei retained) ( Fig.
T98	57997-58113	Epistemic_statement	denotes	Orthokeratosis can be divided into basket weave (the normal pattern in the stratum corneum), compact, and laminated.
T99	58518-58691	Epistemic_statement	denotes	Diffuse parakeratosis can be seen in many chronic dermatoses, especially zinc-responsive dermatosis, dermatophilosis, superficial necrolytic dermatitis, and thallotoxicosis.
T100	58808-58929	Epistemic_statement	denotes	Hyperpigmentation may be focal or diffuse, and confined to the stratum basale or present throughout all epidermal layers.
T101	59075-59176	Epistemic_statement	denotes	Hyperpigmentation must always be cautiously assessed with regard to the animal's normal pigmentation.
T102	59472-59920	Epistemic_statement	denotes	Epidermal hyperplasia may be further specified as irregular (in which the hyperplastic rete ridges are uneven in shape and height), regular or psoriasiform (in which the hyperplastic rete ridges are of even thickness and length), papillated (digitate projections of the epidermis above the skin surface), and pseudocarcinomatous (extreme, irregular hyperplasia that may demonstrate increased mitotic activity and branched or fused rete pegs) ( Fig.
T103	59928-60057	Epistemic_statement	denotes	The process may resemble squamous cell carcinoma; however, there is no cellular atypia, and the basement membrane remains intact.
T104	60121-60529	Epistemic_statement	denotes	It may be associated with congenital or acquired idiopathic defects in melanization (leukoderma, vitiligo), toxic effects of certain chemicals on melanocytes (e.g., mono benzylether of dihydroquinone in rubbers and plastics), inflammatory disorders that affect melanization or destroy melanocytes, hormonal disorders, and dermatoses featuring hydropic degeneration of basal cells (e.g., lupus erythematosus).
T105	60706-60838	Epistemic_statement	denotes	Intracellular edema of the epidermis may affect cells in a laminar fashion, leading to horizontal layers of edematous keratinocytes.
T106	60839-60931	Epistemic_statement	denotes	Severe intracellular edema may result in reticular degeneration and intraepidermal vesicles.
T107	61184-61323	Epistemic_statement	denotes	Hydropic degeneration may result in intrabasal clefts or vesicles, or subepidermal clefts or vesicles because of dermoepidermal separation.
T108	62060-62243	Epistemic_statement	denotes	They are seen most frequently in conjunction with immune-mediated dermatoses, dermatoses associated with tissue eosinophilia, and in panniculitis, such as injection-site panniculitis.
T109	62309-62598	Epistemic_statement	denotes	Mucinosis (myxedema, myxoid degeneration, mucoid degeneration) is an accumulation of dermal ground substance that appears as slightly granular, basophilic material that separates, thins, or replaces dermal collagen fibers and surrounds blood vessels and appendages in H&E-stained sections.
T110	63028-63128	Epistemic_statement	denotes	It may be seen with any acute or subacute inflammatory dermatosis, such as acute contact dermatitis.
T111	64286-64412	Epistemic_statement	denotes	Severe intercellular edema may lead to rupture of the intercellular bridges and the formation of intraepidermal vesicles (Fig.
T112	64422-64542	Epistemic_statement	denotes	Severe spongiotic vesicle formation may disrupt the basement membrane zone in some areas and form subepidermal vesicles.
T113	64629-64801	Epistemic_statement	denotes	Diffuse spongiosis, which also involves the hair follicle outer root sheath, may be seen in other inflammatory disorders, including feline eosinophilic plaque or granuloma.
T114	65108-65228	Epistemic_statement	denotes	Mucinous degeneration may be seen as a focal process in numerous inflammatory, neoplastic, and developmental dermatoses.
T115	65304-65455	Epistemic_statement	denotes	Multinucleated keratinocytes can occasionally be seen in infections by viruses, such as herpesvirus, canine distemper virus, and feline leukemia virus.
T116	65879-65994	Epistemic_statement	denotes	Apoptosis is often used synonymously with individual keratinocyte death that may occur from a variety of processes.
T117	65995-66114	Epistemic_statement	denotes	Individual keratinocyte necrosis can occur in erythema multiforme, graft-versus-host disease, and interface dermatoses.
T118	66115-66250	Epistemic_statement	denotes	Necrosis of the epidermis or dermis may be more extensive due to physical and chemical injury, or to interference with vascular supply.
T119	66484-66697	Epistemic_statement	denotes	It can occur without significant involvement of the overlying dermis and epidermis (e.g., sterile nodular panniculitis, feline nutritional steatitis), or can be involved by extension of inflammation of the dermis.
T120	66698-66871	Epistemic_statement	denotes	Fat micropseudocyst formation and lipocytes containing radially arranged needleshaped clefts can be seen with subcutaneous fat sclerosis and idiopathic sterile panniculitis.
T121	67045-67165	Epistemic_statement	denotes	Papillomatosis is associated with epidermal hyperplasia and is seen with chronic inflammatory and neoplastic dermatoses.
T122	67479-67510	Epistemic_statement	denotes	It can result from any process
T123	67511-67642	Epistemic_statement	denotes	Used commonly in the diagnoses of neoplasms, a system of pattern analysis is also applied to inflammatory/nonneoplastic dermatoses.
T124	67643-67738	Epistemic_statement	denotes	Most dermatologic lesions can be grouped into 1 of 10 histologic patterns on low magnification.
T125	68772-68850	Epistemic_statement	denotes	It can be difficult to gauge the importance of each pattern within the biopsy.
T126	68851-69002	Epistemic_statement	denotes	Some patterns are more specific than Transepidermal elimination is a mechanism by which foreign or altered constituents can be removed from the dermis.
T127	69003-69137	Epistemic_statement	denotes	This can be illustrated by the elimination of mineralized collagen across the epidermis and follicular epithelium in calcinosis cutis.
T128	69193-69280	Epistemic_statement	denotes	They may be subcorneal, suprabasilar, subepidermal, or immediately below the epidermis.
T129	69281-69387	Epistemic_statement	denotes	When these lesions contain large numbers of inflammatory cells, they may be referred to as vesicopustules.
T130	69653-69923	Epistemic_statement	denotes	They may be caused by severe intercellular or intracellular edema, ballooning degeneration, acantholysis, hydropic degeneration of basal cells, subepidermal edema, or other factors resulting in dermoepidermal separation, such as the autoantibodies in bullous pemphigoid.
T131	70404-70510	Epistemic_statement	denotes	Severe spongiotic vesiculation may disrupt the basement membrane zone, resulting in subepidermal vesicles.
T132	70788-70961	Epistemic_statement	denotes	When the hair follicle outer root sheath is also involved, feline allergic dermatitides, such as feline eosinophilic plaque and feline eosinophilic granuloma, are suggested.
T133	70962-71124	Epistemic_statement	denotes	• Perivascular dermatitis with epidermal hyperplasia is characterized by various degrees of epidermal hyperplasia and hyperkeratosis with little or no spongiosis.
T134	71485-71615	Epistemic_statement	denotes	The presence of parakeratosis suggests zincresponsive dermatosis, chronic ectoparasite hypersensitivity, or Malassezia dermatitis.
T135	71805-72016	Epistemic_statement	denotes	This pattern can be divided into interface cell poor (interface changes with minimal superficial dermal inflammation) or interface lichenoid (interface changes with a lichenoid band of mononuclear inflammation).
T136	72095-72326	Epistemic_statement	denotes	• The cell-poor interface pattern can be seen in diseases such as dermatomyositis, ischemic dermatopathy, erythema multiforme, drug eruptions, graft-versus-host reactions, bovine viral diarrhea, and bovine pseudolumpy skin disease.
T137	72976-73084	Epistemic_statement	denotes	Caution should be exercised in differentiating interface lichenoid inflammation from lichenoid inflammation.
T138	74133-74407	Epistemic_statement	denotes	The primary cause of superficial perivascular dermatitis is a hypersensitivity reaction, although chronic bacterial infections, viral infections, cornification disorders, and metabolic disease can all demonstrate this pattern at some point during evolution of the condition.
T139	74408-74557	Epistemic_statement	denotes	Perivascular infiltrates containing eosinophils should first be suspected of representing dermatitis, such as ectoparasitism, food allergy, or atopy.
T140	74558-74665	Epistemic_statement	denotes	Focal areas of eosinophilic exocytosis and necrosis ("epidermal nibbles") are suggestive of ectoparasitism.
T141	74666-74843	Epistemic_statement	denotes	Other perivascular dermatitides that may contain eosinophils include zinc-responsive dermatosis, equine multisystemic eosinophilic epitheliotropic disease, and chronic pyoderma.
T142	75131-75160	Epistemic_statement	denotes	rarely in cutaneous lymphoma.
T143	75161-75246	Epistemic_statement	denotes	It can also reflect a chronic stage of a vasculitis that was originally neutrophilic.
T144	75247-75281	Epistemic_statement	denotes	• Eosinophilic vasculitis is rare.
T145	75282-75537	Epistemic_statement	denotes	It is seen most commonly in lesions induced by arthropod insult, drug eruptions, food hypersensitivity, equine axillary nodular necrosis, idiopathic nodular eosinophilic vasculitis in horses, feline eosinophilic granulomas, and rarely in mast cell tumors.
T146	75695-75848	Epistemic_statement	denotes	Nodular and diffuse dermatitis may be characterized by the predominant cell type present (neutrophils, macrophages, lymphocytes, eosinophils, or mixed) .
T147	75849-75960	Epistemic_statement	denotes	The inciting antigen may be an infectious agent, noninfectious material, or the inflammation may be idiopathic.
T148	75961-76084	Epistemic_statement	denotes	Neutrophils predominate in dermal abscesses associated with infectious agents such as bacteria, fungi, algae, and protozoa.
T149	76571-76665	Epistemic_statement	denotes	It can be accompanied by fibrinoid necrosis, thrombosis, hemorrhage, and evidence of ischemia.
T150	76666-76710	Epistemic_statement	denotes	Vasculitis can be immune mediated or septic.
T151	77193-77280	Epistemic_statement	denotes	Vasculitis can also be locally induced by bacterial antigens deposited in vessel walls.
T152	77281-77385	Epistemic_statement	denotes	Vasculitis can further be classified on the basis of the dominant inflammatory cell within vessel walls.
T153	77454-77595	Epistemic_statement	denotes	It should be noted that the inflammatory cell involved often reflects the stage of the disease rather than characterizing a specific disease.
T154	77596-77778	Epistemic_statement	denotes	• Neutrophilic vasculitis is by far the most common type and may be leukocytoclastic (associated with karyorrhexis of neutrophils resulting in "nuclear dust") or nonleukocytoclastic.
T155	77995-78190	Epistemic_statement	denotes	• Lymphocytic vasculitis may be seen with dermatomyositis, malignant catarrhal fever, vaccine-induced panniculitis, and dant finely granular, eosinophilic cytoplasm with ill-defined cell borders.
T156	78575-78780	Epistemic_statement	denotes	In general, these 3 forms of giant cells have little diagnostic specificity, although the Touton variety is strongly indicative of xanthomas, and the Langhans type suggests the need for an acid-fast stain.
T157	78781-79022	Epistemic_statement	denotes	Eosinophils may predominate in feline, canine, and equine eosinophilic granuloma; in certain parasitic dermatoses (habronemiasis, elaeophoriasis, parafilariasis, dirofilariasis, dracunculiasis); in furunculosis, and in hairy vetch toxicosis.
T158	79346-79436	Epistemic_statement	denotes	They may contain eosinophilic, intracytoplasmic inclusions that are called Russell bodies.
T159	79437-79547	Epistemic_statement	denotes	These accumulations of glycoprotein are largely globulin and may be large enough to displace the cell nucleus.
T160	79548-79752	Epistemic_statement	denotes	Reactions to ruptured hair follicles are a common cause of nodular and diffuse pyogranulomatous dermatitis in domestic animals, and any such lesion should be examined for keratinous and epithelial debris.
T161	79753-79901	Epistemic_statement	denotes	All other nodular and diffuse dermatitides should be cultured, examined in polarized light for foreign material, and stained for bacteria and fungi.
T162	79902-79996	Epistemic_statement	denotes	In general, microorganisms are most likely to be found near areas of suppuration and necrosis.
T163	79997-80209	Epistemic_statement	denotes	Intraepidermal vesicles and pustules can be caused by intercellular edema that can be seen in any acute or subacute dermatosis, viral infections, hydropic degeneration of keratinocytes, and by acantholysis ( Fig.
T164	80218-80334	Epistemic_statement	denotes	It can be useful to subdivide this category on the basis of the site of the vesicle or pustule within the epidermis.
T165	80335-80524	Epistemic_statement	denotes	• Subcorneal pustules and vesicles are most commonly seen in pemphigus foliaceus, pustules associated with superficial pyoderma, and eosinophilic pustules resulting from hypersensitivities.
T166	80758-80914	Epistemic_statement	denotes	• Intrabasilar vesicles can be seen in lupus erythematosus, dermatomyositis, erythema multiforme, graft-versus-host disease, and toxic epidermal necrolysis.
T167	81006-81261	Epistemic_statement	denotes	Subepidermal vesicles and pustules may be formed through hydropic degeneration of basal cells, dermoepidermal separation, severe subepidermal edema and/or cellular infiltration, and severe intercellular edema with disruption of the basement membrane zone.
T168	81262-81478	Epistemic_statement	denotes	Caution is warranted when examining older lesions, as re-epithelialization may result in subepidermal vesicles and pustules assuming an intraepidermal location as re-epithelialization forms a pseudobase to a vesicle.
T169	81762-81971	Epistemic_statement	denotes	Ulcers limited to the upper portion of the superficial dermis do not usually result in scarring, whereas virtually all ulcers that extend into the deep dermis result in fibrosis and clinical signs of scarring.
T170	82385-82466	Epistemic_statement	denotes	Likewise, the panniculus can be secondarily involved in deep dermal inflammation.
T171	82467-82820	Epistemic_statement	denotes	Panniculitis may be caused by infectious agents, foreign bodies, vitamin E deficiency, trauma, pancreatic nant), orthokeratotic hyperkeratosis, follicular keratosis, decreased numbers of hair shafts in follicular infundibula, epidermal atrophy, sebaceous gland atrophy, and dermal atrophy (this can be difficult to assess without site-matched controls).
T172	82821-83002	Epistemic_statement	denotes	Atrophic dermatosis is rarely diagnostic for a specific condition but can suggest a group of diseases such as the endocrine dermatoses, the most common cause of atrophic dermatosis.
T173	83003-83114	Epistemic_statement	denotes	It will almost always be necessary to confirm the identity of the endocrinopathy with endocrine function tests.
T174	83115-83311	Epistemic_statement	denotes	Other causes of atrophic dermatoses include ischemia, feline acquired skin fragility, and alopecia X. Follicular and adnexal atrophy can also be secondary, rather than the primary disease process.
T175	83736-83780	Epistemic_statement	denotes	However, it is often sterile and idiopathic.
T176	83781-83979	Epistemic_statement	denotes	Panniculitis can be divided into lobular (fat lobules are primarily involved), septal (interlobular connective tissue septa are primarily involved), and diffuse (both anatomic areas involved) types.
T177	83980-84036	Epistemic_statement	denotes	Septal panniculitis is often associated with vasculitis.
T178	84037-84114	Epistemic_statement	denotes	However, all 3 patterns may be seen in a single lesion from the same patient.
T179	84115-84332	Epistemic_statement	denotes	The majority of inflammatory conditions of the panniculus are granulomatous or pyogranulomatous, and the histologic appearance of panniculitis caused by an infectious agent can be very similar to sterile panniculitis.
T180	84658-84718	Epistemic_statement	denotes	It can also refer to atrophy of the epidermis or the dermis.
T181	84719-84842	Epistemic_statement	denotes	Evaluation of atrophy of the epidermis and dermis should always take into account the site from which the biopsy was taken.
T182	85594-85769	Epistemic_statement	denotes	The literature on ichthyosiform disorders in human medicine is extensive and complex, and, not unlike veterinary medicine, molecular tests are not available for all disorders.
T183	87168-87260	Epistemic_statement	denotes	Neither ichthyosis vulgaris nor X-linked ichthyosis has been documented in domestic animals.
T184	87453-87620	Epistemic_statement	denotes	In humans, ARCI may manifest as 1 of 3 clinical forms: lamellar ichthyosis (LI), nonbullous congenital ichthyosiform erythroderma (CIE), and harlequin ichthyosis (HI).
T185	87621-87736	Epistemic_statement	denotes	The phenotypes of LI and CIE are often overlapping, and some patients may switch phenotypes with age and treatment.
T186	88073-88193	Epistemic_statement	denotes	Although LI is often associated with the transglutaminase 1 (TGM1) gene, it is by no means specific for a TGM1 mutation.
T187	88194-88390	Epistemic_statement	denotes	To date, 8 genes have been associated with ACRI: TGM1, ABCA12, ABHD5 (CG158), 2 lipoxygenases (ALOXE3 and ALOX12B), a NIPA-like domain containing 4 (NIPAL4 or ICTHYIN), LIPN, CYP4F22, and PNPLA-1.
T188	88391-88630	Epistemic_statement	denotes	The diagnosis of ichthyosiform disorders is based on the following: signalment, history, character and distribution of the scale, presence or absence of extracutaneous lesions, and skin biopsy analysis, perhaps including molecular testing.
T189	88631-88722	Epistemic_statement	denotes	For breeding dogs, molecular testing, if available, may be needed to identify carrier dogs.
T190	88723-88938	Epistemic_statement	denotes	A pathologist should be able to narrow the mutational causes by determining if the disorder is epidermolytic (rare but uniquely associated with keratin mutations) or nonepidermolytic (more common and less specific).
T191	89015-89113	Epistemic_statement	denotes	They may be hereditary or result from other factors that were present during development in utero.
T192	89114-89375	Epistemic_statement	denotes	Various environmental influences, such as infectious agents, nutrient imbalances, toxic chemicals and plants, and ambient temperature, present during gestation, can bring about abnormalities in the skin and hair that are present at birth but are not hereditary.
T193	89480-89581	Epistemic_statement	denotes	Congenital abnormalities of the skin may be associated with abnormalities of other tissues or organs.
T194	89582-89786	Epistemic_statement	denotes	In contrast, although they are genetically determined, some hereditary abnormalities of skin (genodermatoses) are not apparent at birth and may instead be manifested later in life, that is, tardive onset.
T195	89787-89865	Epistemic_statement	denotes	For example, color-dilution alopecia may not be evident until early adulthood.
T196	90097-90238	Epistemic_statement	denotes	New genetic disorders are being recognized at an increasing rate as the degree of diagnostic sophistication of veterinary medicine has grown.
T197	90386-90637	Epistemic_statement	denotes	Once an analogous genetic disease is identified in animals, affected animals may be used to gain new knowledge regarding the genetics, pathogenesis, or treatment of the condition, thereby producing reciprocal benefits for both human and animal health.
T198	90903-91002	Epistemic_statement	denotes	The gene is thought to play a role in lipid organization and metabolism within the outer epidermis.
T199	91076-91169	Epistemic_statement	denotes	Unlike the Golden Retriever, the Bulldogs consistently develop clinical signs before weaning.
T200	91590-91632	Epistemic_statement	denotes	Malassezia yeast overgrowth may be severe.
T201	91763-91846	Epistemic_statement	denotes	The clinical presentation may be misinterpreted as nonseasonal atopic skin disease.
T202	91847-91901	Epistemic_statement	denotes	Occasional adult dogs may have footpad hyperkeratosis.
T203	91902-92055	Epistemic_statement	denotes	The disorder has been linked to ICHTHYN, and similar to the PLPLA1 mutation in Golden Retrievers, is likely related to lipid metabolism in the epidermis.
T204	92763-92988	Epistemic_statement	denotes	A number of other breeds have been diagnosed with NI on light microscopy and clinical examination (Soft-coated Wheaten Terriers, West Highland White Terriers), but further molecular characterizations have not been documented.
T205	92989-93070	Epistemic_statement	denotes	Many cases are likely confirmed on skin biopsy and do not receive further workup.
T206	93071-93267	Epistemic_statement	denotes	A congenital and familial form of keratoconjunctivitis sicca with scaling has been documented in Cavalier King Charles Epidermolytic ichthyosis is also referred to as epidermolytic hyperkeratosis.
T207	93698-93783	Epistemic_statement	denotes	The biochemical basis is most often associated with a defect in the K1 and K10 genes.
T208	94123-94279	Epistemic_statement	denotes	To date, the nonepidermolytic forms of ichthyosis, which have been characterized in dogs, have been documented or presumed to be autosomal recessive traits.
T209	94280-94511	Epistemic_statement	denotes	Nonepidermolytic ichthyosis (NI) is not necessarily recessive (e.g., X-linked ichthyosis and autosomal dominant ichthyosis vulgaris are also nonepidermolytic); however, these disorders have yet to be documented in domestic animals.
T210	94512-94643	Epistemic_statement	denotes	Veterinary pathologists currently label these ARCI disorders by their breed predilection, a practice that may change in the future.
T211	94763-94938	Epistemic_statement	denotes	The clinical presentation consists of large, soft, white-to-gray adherent scale that is prominent on the trunk and may be associated with ventral hyperpigmentation (eFig.6-2).
T212	95185-95290	Epistemic_statement	denotes	Golden Retrievers are typically diagnosed at <1 year of age; however, adult-onset cases are not uncommon.
T213	95291-95420	Epistemic_statement	denotes	Some dogs develop secondary bacterial folliculitis, which may lead to pruritus and clinical confusion with allergic skin disease.
T214	95421-95500	Epistemic_statement	denotes	The disease may wax and wane with periodic bouts of exacerbation and remission.
T215	95501-95542	Epistemic_statement	denotes	Golden Retriever ichthyosis is caused by
T216	95543-95642	Epistemic_statement	denotes	Wattles (tassels), similar to those seen in goats, occur occasionally in swine and rarely in sheep.
T217	95868-95924	Epistemic_statement	denotes	They are 5-7 cm long and may be unilateral or bilateral.
T218	98179-98229	Epistemic_statement	denotes	A recessive mode of inheritance has been proposed.
T219	98346-98498	Epistemic_statement	denotes	An X-linked dominant mode of inheritance has been suggested in Rottweilers because the 5 reported dogs were female, and no male relatives were affected.
T220	99089-99225	Epistemic_statement	denotes	In Labradors, the condition may be confused with a presumably immune-mediated adult-onset form of mural folliculitis with parakeratosis.
T221	99489-99537	Epistemic_statement	denotes	The mode of inheritance has not been determined.
T222	99659-99776	Epistemic_statement	denotes	Ichthyosis has been reported in many breeds of cattle, and the mode of inheritance appears to be autosomal recessive.
T223	99914-100099	Epistemic_statement	denotes	However, the underlying molecular defect(s) is unknown, and it is uncertain whether the forms are distinct diseases or merely represent variations in expression of a single abnormality.
T224	100660-100746	Epistemic_statement	denotes	The skin is dry, hard, and inflexible like old leather, and may be prominently folded.
T225	101151-101380	Epistemic_statement	denotes	Histologic changes in the skin are mild to moderate perivascular dermatitis, moderate to marked acanthosis that may be accompanied by pallor of the superficial epidermis, and marked diffuse parakeratotic hyperkeratosis (see eFig.
T226	101388-101534	Epistemic_statement	denotes	There may also be neutrophilic exocytosis, intraepidermal neutrophilic pustules, and serocellular crusts containing bacterial cocci and/or yeasts.
T227	101610-101774	Epistemic_statement	denotes	If this information is not available, differential diagnoses include superficial necrolytic dermatitis, zinc-responsive dermatosis, and generic dog food dermatosis.
T228	101775-101911	Epistemic_statement	denotes	However, parakeratosis is less severe in these diseases, and superficial epidermal necrolysis is not a feature of lethal acrodermatitis.
T229	101912-102175	Epistemic_statement	denotes	Much of the older literature uses the term epitheliogenesis imperfecta (EI) to describe congenital mechanobullous conditions in many species; however, many of these conditions would be more appropriately termed epidermolysis bullosa in the current classification.
T230	102316-102460	Epistemic_statement	denotes	In swine, aplasia cutis congenita (also called epitheliogenesis imperfecta) is very rare and a clinically distinct, recessively inherited trait.
T231	102577-102662	Epistemic_statement	denotes	Piglets with small focal lesions may survive but are smaller than normal littermates.
T232	102898-102948	Epistemic_statement	denotes	Piglets may have fluid-filled subcutaneous bullae.
T233	102949-102982	Epistemic_statement	denotes	An underlying cause is not known.
T234	102983-103228	Epistemic_statement	denotes	Epidermolysis bullosa is divided into 3 broad groups based on the ultrastructural level of the skin cleavage: epidermolysis bullosa simplex (EBS; epidermolytic epidermolysis bullosa), then appear around the eyes, ears, and intermandibular space.
T235	103386-103454	Epistemic_statement	denotes	The flanks, perianal area, and ventral abdomen may also be affected.
T236	103455-103599	Epistemic_statement	denotes	The hair may lighten in color, a change that may be especially prominent around the eyes and resemble the spectacle lesion of copper deficiency.
T237	103600-103671	Epistemic_statement	denotes	Affected calves are lethargic, drool, and may have difficulty suckling.
T238	103912-104067	Epistemic_statement	denotes	This disease is associated with impaired intestinal zinc absorption caused by abnormal function of a protein belonging to a family of zinc-uptake proteins.
T239	104068-104153	Epistemic_statement	denotes	Acrodermatitis enteropathica and HZD are associated with defects in the gene SLC39A4.
T240	104154-104287	Epistemic_statement	denotes	Oral zinc supplementation effects a complete reversal of clinical signs and may restore thymic morphology if instituted early enough.
T241	104567-104720	Epistemic_statement	denotes	A cysteine-rich intestinal protein (CRIP) has been identified in the liganddependent pathway and has been suggested as being defective in this condition.
T242	105168-105241	Epistemic_statement	denotes	Neutrophilic exocytosis and superficial bacterial cocci may be prominent.
T243	105242-105434	Epistemic_statement	denotes	Lethal acrodermatitis of Bull Terrier dogs is also thought to be caused by an abnormality in zinc absorption or metabolism; however, zinc supplementation fails to produce clinical improvement.
T244	106734-106913	Epistemic_statement	denotes	Extracutaneous postmortem lesions consist of a small or absent thymus and may also include a high, arched palate and 533.e1 eFigure 6-5 Lethal acrodermatitis of Bull Terrier dogs.
T245	107466-107658	Epistemic_statement	denotes	Whereas hemidesmosomes may be normal or reduced in size and number in the non-Herlitz type, they are markedly reduced or absent with an absent sub-basal dense plate in the Herlitz type of JEB.
T246	107995-108147	Epistemic_statement	denotes	Affected animals usually develop lesions shortly after birth; however, in some cases, the disease is not evident until the animal is several months old.
T247	108148-108264	Epistemic_statement	denotes	Initial lesions consist of vesicles and bullae, but they quickly rupture, and only ulcers may be evident clinically.
T248	108571-108716	Epistemic_statement	denotes	Lesions may be induced accidentally by rough handling of an affected animal or intentionally for diagnostic purposes by gentle frictional trauma.
T249	108987-109150	Epistemic_statement	denotes	Even in the epidermolytic form of epidermolysis bullosa, the cleavage is usually so low in the epidermis that the vesicle appears subepidermal in routine sections.
T250	109151-109319	Epistemic_statement	denotes	PAS staining to visualize the basement membrane zone may be helpful in determining the level of cleavage, but definitive diagnosis requires ultrastructural examination.
T251	109320-109493	Epistemic_statement	denotes	Basement membrane antigen mapping by immunofluorescence or immunohistochemistry may be a diagnostic adjunct or alternative to electron microscopy to establish the diagnosis.
T252	110075-110275	Epistemic_statement	denotes	In calves, epidermolysis bullosa (termed EI) has been reported in many breeds and appears to be an autosomal recessive trait, and it is seen most often in herds in which there is extensive inbreeding.
T253	110494-110557	Epistemic_statement	denotes	JEB may be further classified into Herlitz or non-Herlitz type.
T254	110901-111073	Epistemic_statement	denotes	The clinical presentation may range from minimal localized involvement of hands and feet to severe, life-threatening generalized blistering with extracutaneous involvement.
T255	111270-111398	Epistemic_statement	denotes	In animals, epidermolysis bullosa has been reported rarely and, in most instances, has led to the death of affected individuals.
T256	112052-112285	Epistemic_statement	denotes	• In junctional epidermolysis bullosa, clefting occurs within the lamina lucida because of abnormalities of the anchoring filament-hemidesmosome complexes, which may be reduced in number and poorly formed or may be completely absent.
T257	113193-113351	Epistemic_statement	denotes	The PASpositive basement membrane zone remained attached to the epithelium and formed the roof of the vesicle, suggestive of dystrophic epidermolysis bullosa.
T258	113433-113609	Epistemic_statement	denotes	Ultrastructural examination of skin from the Swiss lambs indicated that the splitting was below the lamina densa and that anchoring fibrils were absent or rare and rudimentary.
T259	113610-113848	Epistemic_statement	denotes	Antigen mapping of the lesion identified laminin and type IV collagen at the roof of the cleft, which confirms sublamina densa blistering; and no type VII collagen, the major structural component of anchoring fibrils, could be identified.
T260	113849-113929	Epistemic_statement	denotes	These findings are consistent with the dystrophic form of epidermolysis bullosa.
T261	114126-114325	Epistemic_statement	denotes	The unaffected twin brother of this buck was bred over 5 consecutive years with the dam and produced 12 kids, 4 of which were affected with DEB, suggesting an autosomal recessive mode of inheritance.
T262	115115-115185	Epistemic_statement	denotes	The proximal esophagus may also be affected and hooves may be lacking.
T263	115430-115535	Epistemic_statement	denotes	Extracutaneous lesions are rare, and included ocular lesions in one foal and dental dysplasia in another.
T264	115713-115834	Epistemic_statement	denotes	Ultrastructurally, the separation is located within the lamina lucida, indicating that hemidesmosomes are underdeveloped.
T265	115900-116160	Epistemic_statement	denotes	The mutation responsible-a cytosine insertion in exon 10 of the LAMC2 gene-has also been identified in JEB phenotype horses in 2 commonly; however, any portion of the body may be affected as well as the squamous epithelium of the muzzle, lips, and oral cavity.
T266	116161-116219	Epistemic_statement	denotes	Hooves and dewclaws may be missing or incompletely formed.
T267	117404-117548	Epistemic_statement	denotes	Three animals kept under laboratory conditions showed gradual improvement in severity of lesions, but rough handling could still elicit lesions.
T268	119380-119658	Epistemic_statement	denotes	A congenital bullous disease suggestive of dystrophic epidermolysis bullosa has been described in Suffolk and South Dorset Down lambs in New Zealand, Scottish Blackface lambs, and lifelong history of trauma-induced ulcers and scars over pressure points of limbs and on footpads.
T269	120289-120343	Epistemic_statement	denotes	Epidermolysis bullosa appears to be very rare in cats.
T270	122573-122731	Epistemic_statement	denotes	A mutation in the collagen VII encoding gene COL7A1 was suggested as the cause, because this gene is mutated in all subsets of DEB in affected human patients.
T271	122793-122866	Epistemic_statement	denotes	In American Saddlebred horses, the mutation has been identified in LAMA3.
T272	122951-123124	Epistemic_statement	denotes	However, the initial cases reported as epidermolysis bullosa simplex in young Collies are now thought to represent a mild form of dermatomyositis with unrecognized myositis.
T273	123424-123500	Epistemic_statement	denotes	Non-Herlitz (nonlethal) JEB has been documented in a 4-year-old mongrel dog.
T274	123974-124083	Epistemic_statement	denotes	Junctional EB in German Shorthaired Pointers is autosomal recessive and has been proposed as an animal model.
T275	124300-124434	Epistemic_statement	denotes	The disease is associated with reduced expression of laminin 5 and is caused by a mutation in the LAMA3 gene for the laminin α3 chain.
T276	124435-124597	Epistemic_statement	denotes	Dystrophic epidermolysis bullosa (DEB), associated with mutation in the gene encoding type VII collagen (COL7A1), has been characterized in Golden Retriever dogs.
T277	125614-125721	Epistemic_statement	denotes	Further studies have shown that keratinocytes in lesional and nonlesional skin have depleted SERCA2 stores.
T278	125722-125852	Epistemic_statement	denotes	Although the precise mechanism is not known, depletion of calcium stores may delay exit from the cell cycle and enhance apoptosis.
T279	125853-125986	Epistemic_statement	denotes	Thus the clinical appearance, histologic features, and SERCA2 abnormality suggest the disease in dogs is more similar to DD than HHD.
T280	126415-126589	Epistemic_statement	denotes	The condition is associated with a PKP1 mutation and loss of plakophilin-1 in desmosomal attachments as well as an abnormal arrangement of desmoplakin and keratins 10 and 14.
T281	128068-128263	Epistemic_statement	denotes	Although the clinical presentation of these cases was typical of epidermolysis bullosa, the histologic and ultrastructural features were unlike those of the common forms of epidermolysis bullosa.
T282	128264-128504	Epistemic_statement	denotes	However, some variants of epidermolysis bullosa simplex in humans are characterized by cleft formation with acantholysis in the middle or upper epidermis, and in some instances, cells contain round clumps within their cytoplasm produced by
T283	128505-128597	Epistemic_statement	denotes	A dominantly inherited epidermal acantholytic disease has been described in English Setters.
T284	128598-128986	Epistemic_statement	denotes	The disease was initially compared to Hailey-Hailey disease (HHD) in humans, but current thought is that the disorder is more likely a form of Darier disease (DD) In humans, autosomal dominant mutations in genes that encode calcium pumps are responsible for both HHD (SPCA1: secretory calcium/magnesium ATPase isoform) and DD (SERCA2: sarcoendoplasmic reticulum calcium ATPase isoform 2).
T285	130461-130633	Epistemic_statement	denotes	The clinical appearance of the lesions was not typical HHD, but the histologic and ultrastructural features were thought to be similar to benign familial chronic pemphigus.
T286	131296-131354	Epistemic_statement	denotes	Animals may not grow well and may have a wild temperament.
T287	131729-131828	Epistemic_statement	denotes	The condition appears to be inherited as a simple autosomal recessive trait in all breeds affected.
T288	132282-132424	Epistemic_statement	denotes	Histologic changes include small, inactive hair follicles, deformed dermal papillae lacking a vascular network, and degenerative sweat glands.
T289	132425-132682	Epistemic_statement	denotes	A HAD syndrome, with hypotrichosis, almost complete lack of teeth, and complete absence of eccrine nasolabial glands, has been observed in a family of German Holsteins; similar anomalies in humans are known as X-linked anhidrotic ectodermal dysplasia (ED1).
T290	133211-133245	Epistemic_statement	denotes	Calves may become normal with age.
T291	133405-133580	Epistemic_statement	denotes	Inherited epidermal dysplasia, also called baldy calf syndrome, is a lethal disease of Holstein-Friesian calves that is likely inherited as a single autosomal recessive trait.
T292	133581-133703	Epistemic_statement	denotes	The disease causes loss of condition and skin, horn, and hoof lesions that can be confused with inherited zinc deficiency.
T293	133704-133958	Epistemic_statement	denotes	Calves appear normal at birth, but at 1-2 months of age, they begin to lose condition despite normal appetite, and develop generalized hair loss and patchy areas of scaly, wrinkled, thickened skin over the neck, shoulders, flanks, and on pressure points.
T294	134406-134507	Epistemic_statement	denotes	Congenital hypotrichosis of Hereford cattle is thought to be due to a simple autosomal dominant gene.
T295	134549-134735	Epistemic_statement	denotes	Calves have thin, pliable skin, extremely curly facial hair, and may have sparse pelage of thin soft curly, easily broken and epilated hairs, or they may be aggregation of tonofilaments.
T296	135017-135114	Epistemic_statement	denotes	It is usually sparse, short and fine, or coarse and wiry, brittle, and easily broken or epilated.
T297	135115-135229	Epistemic_statement	denotes	Histologic changes are variable, likely a reflection of the different mutations responsible for the hypotrichosis.
T298	135494-135577	Epistemic_statement	denotes	Iodine deficiency can cause goiter and hypotrichosis in piglets, lambs, and calves.
T299	135578-135741	Epistemic_statement	denotes	Adenohypophyseal hypoplasia in Guernseys and Jerseys, and maternal ingestion of Veratrum album by Japanese cattle, has been associated with hairlessness in calves.
T300	135742-135917	Epistemic_statement	denotes	In addition, alopecia of various degrees has been associated with intrauterine infection with bovine viral diarrhea virus in calves and classical swine fever virus in piglets.
T301	136636-136735	Epistemic_statement	denotes	Sebaceous glands and arrector pili muscles appear normal; sweat glands undergo cystic degeneration.
T302	137126-137237	Epistemic_statement	denotes	Although initially healthy, all affected kittens in one report died by 13 weeks of age from various infections.
T303	137238-137453	Epistemic_statement	denotes	Postmortem examination of some of the affected Birman kittens revealed thymic aplasia and lymphoid depletion of paracortical regions of lymph nodes, spleen, and Peyer's patches, suggesting an immunologic deficiency.
T304	137582-137707	Epistemic_statement	denotes	Sebaceous glands were normal, but sweat glands were hypoplastic and in decreased number, and arrector pili muscles were rare.
T305	137708-137810	Epistemic_statement	denotes	Hereditary hypotrichosis is recognized in piglets, and there may be both dominant and recessive forms.
T306	137811-137970	Epistemic_statement	denotes	The dominant form is thought to be lethal in homozygotes; it is characterized histologically by a decreased number of hair follicles, and most appear atrophic.
T307	137971-138071	Epistemic_statement	denotes	Congenital hypotrichosis is thought to be a simple autosomal recessive trait in polled Dorset sheep.
T308	138235-138317	Epistemic_statement	denotes	Congenital hypotrichosis has been described in a Percheron, but is rare in horses.
T309	138318-138360	Epistemic_statement	denotes	Congenital hypotrichosis is rare in goats.
T310	138361-138638	Epistemic_statement	denotes	Drögemüller C, et al Hypotrichosis associated with pigmentary alterations Generalized or regional alopecia attributed to follicular dysplasias that include histologic evidence of pigment abnormalities have been frequently described in dogs and less frequently in other species.
T311	138693-139058	Epistemic_statement	denotes	The first of these 2 categories is color dilution alopecia, described in color-dilute animals of breeds such as the Doberman Pinscher, Irish Setter, Dachshund, Chow Chow, Poodle, Whippet, Italian Greyhound, Boston Terrier, Chihuahua, Saluki, Yorkshire Terrier, and mongrels, in which the onset of alopecia can be tardive, generally ranging from 4 months to 3 years.
T312	139059-139139	Epistemic_statement	denotes	Puppies are born with normal hair, but develop slowly progressive alopecia (Fig.
T313	139148-139264	Epistemic_statement	denotes	Pedigree analysis in colordilute Dachshunds suggests this disorder may be inherited as an autosomal recessive trait.
T314	139562-139656	Epistemic_statement	denotes	There can be some hair follicle atrophy in chronic cases; however, this is a secondary change.
T315	140000-140091	Epistemic_statement	denotes	Arrector pili muscles are reduced in number and frequently not associated with hair shafts.
T316	140092-140223	Epistemic_statement	denotes	Ultrastructural examination indicates that the giant trichohyaline granules lack normal microfilament and macrofilament structures.
T317	140841-140933	Epistemic_statement	denotes	Affected calves also have nonregenerative anemia and fail to grow despite a normal appetite.
T318	141811-141939	Epistemic_statement	denotes	X-linked hypohidrotic ectodermal dysplasia (XHED) has been documented in dogs and the inheritance confirmed by breeding studies.
T319	142158-142243	Epistemic_statement	denotes	The lack of hair is apparent on the dorsal head, ventrum, and dorsal tail base (eFig.
T320	142406-142500	Epistemic_statement	denotes	Hairless areas may have decreased adnexal density as well as partial to complete adnexal loss.
T321	142699-142821	Epistemic_statement	denotes	This protein is thought to control some epithelialmesenchymal cell interactions that regulate development of the ectoderm.
T322	142945-143099	Epistemic_statement	denotes	A semidominant form of ectodermal dysplasia has been documented in congenitally hairless breeds (Mexican and Peruvian hairless dogs, Chinese Crested dog).
T323	143100-143292	Epistemic_statement	denotes	The disorder has been associated with a member of the forkhead box 539.e1 eFigure 6-7 Patterned hairlessness on the dorsum of the head of a dog with X-linked hypohidrotic ectodermal dysplasia.
T324	143472-143602	Epistemic_statement	denotes	Coatcolor-linked hair follicle dysplasia has also been described in buckskin Holstein cows (color-dilute tan-and-white Holsteins).
T325	144055-144248	Epistemic_statement	denotes	Black hair follicular dysplasia is thought to be an autosomal inherited disorder in mongrel puppies, and is thought to have a genetic component in some purebred animals such as Bearded Collies.
T326	144369-144472	Epistemic_statement	denotes	A difference in the appearance of the melanin clumps in whole mounts of hair shafts has been suggested.
T327	144473-144658	Epistemic_statement	denotes	In Greater Musterlanders, the hair shaft defect appears to be associated with inadequate and disorganized melanosome transfer to keratinocytes, with resultant melanin clumping (see Fig.
T328	144667-144828	Epistemic_statement	denotes	There are other follicular dysplasias associated with pigment abnormalities that do not fall easily into these 2 categories, but have similar histologic changes.
T329	144951-145053	Epistemic_statement	denotes	These are not color-dilute dogs, and the onset can be tardive, generally between 3 months and 5 years.
T330	145681-145847	Epistemic_statement	denotes	Follicular dysplasia has been described in Weimaraners, in which affected young adults had progressive alopecia of the trunk with recurrent folliculitis/furunculosis.
T331	145848-145962	Epistemic_statement	denotes	similar to color-dilution alopecia in dogs has been described in cattle as cross-related congenital hypotrichosis.
T332	145963-146116	Epistemic_statement	denotes	This has been reported in crosses involving Simmental, Gelbvieh, and Charolais cattle, most common in the Simmental-Angus and Simmental-Holstein crosses.
T333	146117-146198	Epistemic_statement	denotes	The condition appears in calves that have color-dilute (gray or chocolate) coats.
T334	146199-146282	Epistemic_statement	denotes	The affected Dermatomyositis has been identified in Shelties in the United Kingdom.
T335	146283-146429	Epistemic_statement	denotes	The disease has not been characterized as well in this breed; but it appears that myositis is a less prominent feature of the disease in Shelties.
T336	146730-147147	Epistemic_statement	denotes	The histologic changes of ischemic dermatopathy can be categorized into 5 subtypes: (1) canine familiar dermatomyositis, (2) juvenile-onset ischemic dermatopathy (similar to canine familial dermatomyositis except for the breed predispositions), (3) focal postrabies vaccination reaction, (4) generalized vaccine-induced ischemic dermatopathy, and (5) adult-onset non-vaccine-induced generalized ischemic dermatopathy.
T337	147148-147206	Epistemic_statement	denotes	The cause and pathogenesis of dermatomyositis are unknown.
T338	147207-147339	Epistemic_statement	denotes	The primary target is thought to be capillary endothelium, although histologic evidence of vessel wall inflammation is often absent.
T339	147443-147617	Epistemic_statement	denotes	Variation in expression of dermatomyositis in dogs suggests that factors other than simple autosomal dominant inheritance are involved in the etiopathogenesis of the disease.
T340	147618-147780	Epistemic_statement	denotes	Immunologic mechanisms are thought to be involved in this disease in humans, and both cell-mediated and humoral immunity have been implicated in the pathogenesis.
T341	147781-148138	Epistemic_statement	denotes	In Collies with dermatomyositis, serum levels of circulating immune complexes were found to be increased above normal before clinical disease was evident; the onset and severity of dermatitis and myositis correlated with the serum levels of circulating immune complexes and IgG, and circulating immune complex levels decreased to normal as disease resolved.
T342	148139-148240	Epistemic_statement	denotes	These findings suggest that the immune complexes initiated inflammation rather than resulted from it.
T343	148241-148378	Epistemic_statement	denotes	IgG was identified as the immunoglobulin component of the immune complexes, but the identity of the antigen component was not determined.
T344	148379-148546	Epistemic_statement	denotes	Dermatomyositis has been associated with viral, bacterial, and Toxoplasma infections, but infectious agents are generally not isolated from tissues of affected people.
T345	148547-148678	Epistemic_statement	denotes	Crystalline structures, suggestive of picornaviruses, have been seen in endothelial cells of muscle from severely affected Collies.
T346	148679-148818	Epistemic_statement	denotes	Cases in humans have also occurred following immunization, therapy with various drugs, during pregnancy, and in association with neoplasia.
T347	149242-149346	Epistemic_statement	denotes	Mucous membranes and mucocutaneous junctions may be transiently involved early in the course of disease.
T348	149347-149373	Epistemic_statement	denotes	Pawpad ulceration is rare.
T349	149469-149632	Epistemic_statement	denotes	In mildly to In cattle, follicular dysplasia has been reported in black Angus and black Angus-Brahman crosses; the histologic changes are similar to those in dogs.
T350	149633-149814	Epistemic_statement	denotes	These cattle are all black animals that are not phenotypically color dilute; however, there is adult onset of alopecia that is more commonly associated with color-dilution alopecia.
T351	149815-150188	Epistemic_statement	denotes	In view of the dysplasias in Portuguese Water dogs, black-and-red Doberman Pinschers, and black Angus and their crosses that occur in animals not phenotypically color dilute but that can have adult onset, it is quite possible that separation of follicular dysplasias with pigmentary alteration into color-dilution alopecia and black hair follicular dysplasia is artificial.
T352	150189-150412	Epistemic_statement	denotes	It is likely that these histologically similar follicular dysplasias are subtypes of a single process; however, until the mechanism underlying follicular dysplasia is characterized, the classification is somewhat arbitrary.
T353	150413-150429	Epistemic_statement	denotes	Cerundolo R, et
T354	150430-150523	Epistemic_statement	denotes	Congenital hypertrichosis, a condition characterized by an excessive amount of hair, is rare.
T355	150829-150947	Epistemic_statement	denotes	High environmental temperature during gestation has been associated with an unusual hairy appearance of newborn lambs.
T356	150948-151074	Epistemic_statement	denotes	The lambs are small, and most do not survive to weaning; the histologic appearance of this abnormality has not been described.
T357	152029-152079	Epistemic_statement	denotes	A similar disease, referred to as dermatomyositis-
T358	152080-152183	Epistemic_statement	denotes	Further reading The histologic changes in the skin are variable and may be quite subtle or nonspecific.
T359	152558-152708	Epistemic_statement	denotes	Diagnostically useful artifactual dermal-epidermal separation may be induced at the margins of the section by the shearing action of the punch biopsy.
T360	153244-153410	Epistemic_statement	denotes	The most consistently present histologic abnormalities are follicular atrophy and perifollicular inflammation that may be accompanied by perifollicular fibrosis (Fig.
T361	153984-154103	Epistemic_statement	denotes	A defect in any one of these skin molecules can result in structural and functional abnormalities of the entire tissue.
T362	154104-154280	Epistemic_statement	denotes	Inherited connective tissue disorders of skin may consist of abnormalities involving only one of these components, or there may be concurrent alterations in several components.
T363	154281-154512	Epistemic_statement	denotes	Hereditary collagen dysplasia, the most commonly recognized connective tissue disease, is a complex group of disorders of collagen that results in decreased tensile strength of the skin and may also affect other connective tissues.
T364	154513-154834	Epistemic_statement	denotes	Alterations in elastic fibers and ground substance may accompany some forms of collagen dysplasia, but there moderately affected dogs, lesions may resolve spontaneously in 6-12 months, whereas in severely affected dogs, lesions may regress but do not usually resolve completely, and disease may be lifelong and extensive.
T365	155030-155105	Epistemic_statement	denotes	Lesions may be exacerbated by estrus, parturition, or exposure to sunlight.
T366	155106-155344	Epistemic_statement	denotes	Although cases of adult-onset dermatomyositis have been reported, it is likely that at least some of these dogs had mild transient lesions that were overlooked when they were pups and subsequently developed more obvious disease as adults.
T367	155547-155668	Epistemic_statement	denotes	However, because of the dolichocephalic shape of the Collie head, mild temporal or masseter muscle atrophy may be missed.
T368	155897-156025	Epistemic_statement	denotes	Generalized symmetrical muscle atrophy, weakness, and exercise intolerance may develop in moderately and severely affected dogs.
T369	156026-156065	Epistemic_statement	denotes	Megaesophagus may develop in some dogs.
T370	156066-156168	Epistemic_statement	denotes	Various additional abnormalities may accompany skin and muscle lesions in more severely affected dogs.
T371	156238-156359	Epistemic_statement	denotes	Conjunctivitis may develop in dogs with severe periocular skin lesions or because of facial palsy and inability to blink.
T372	156507-156645	Epistemic_statement	denotes	Secondary bacterial pyoderma, septicemia, or megaesophagus with secondary aspiration pneumonia may develop in more severely affected dogs.
T373	156646-156703	Epistemic_statement	denotes	Demodicosis may also be present and complicate diagnosis.
T374	157619-157701	Epistemic_statement	denotes	Inheritance may be autosomal dominant, autosomal recessive, or X-linked recessive.
T375	157702-157869	Epistemic_statement	denotes	In animals, clinical disease has been restricted almost exclusively to skin abnormalities and has been characterized in only a few breeding colonies or herd outbreaks.
T376	157870-158008	Epistemic_statement	denotes	Most instances of collagen dysplasia occur in single animals, and the molecular defect and mode of inheritance are usually not determined.
T377	158456-158567	Epistemic_statement	denotes	Extracutaneous signs, such as joint laxity and ocular abnormalities, have been reported in animals only rarely.
T378	158568-158651	Epistemic_statement	denotes	The skin is usually soft and velvety, hyperextensible, and may hang in loose folds.
T379	159188-159323	Epistemic_statement	denotes	In general, the disease tends to be most severe in sheep, less severe in cattle, followed by dogs and cats, and least severe in horses.
T380	159477-159694	Epistemic_statement	denotes	In some cases, abnormalities are evident at the light microscopic level, but frequently none are found or the differences are subtle and difficult to determine except by comparison to a breed- and age-matched control.
T381	159695-159816	Epistemic_statement	denotes	The dermis may be normal, thinner than normal, or thicker than normal because of an increased amount of ground substance.
T382	159817-159912	Epistemic_statement	denotes	Collagen fibers may be widely separated, finer and paler than normal, and haphazardly arranged.
T383	159913-159986	Epistemic_statement	denotes	Rarely, increased numbers of elastic fibers are seen with elastic stains.
T384	160064-160154	Epistemic_statement	denotes	Abnormal collagen fibers may stain unevenly with collagen stains such as Masson trichrome.
T385	160155-160254	Epistemic_statement	denotes	Instead of the uniform blue staining of normal collagen, the abnormal collagen may have a red core.
T386	160255-160403	Epistemic_statement	denotes	This staining feature is not unique to collagen dysplasia, however, as uneven collagen staining also occurs with degenerative disorders of collagen.
T387	160558-160642	Epistemic_statement	denotes	In longitudinal sections, collagen fibrils may be loosely wound and flat or helical.
T388	160643-160756	Epistemic_statement	denotes	In crosssection, they may have several irregular thin projecting arms that give them a "hieroglyphic" appearance.
T389	160757-160879	Epistemic_statement	denotes	This appearance are also diseases in which an abnormality of the elastic fibers or ground substance appears to be primary.
T390	161683-161902	Epistemic_statement	denotes	In Border-Leicester-Southdown crossbred lambs, the biochemical abnormality was not determined, but it did not appear to be a procollagen peptidase deficiency because there was no increase in dermal procollagen detected.
T391	162102-162222	Epistemic_statement	denotes	Gross examination of the skin indicates that the dermis is moist and thicker than normal, with a jelly-like consistency.
T392	162545-162631	Epistemic_statement	denotes	No skin hyperelasticity or joint hypermobility are associated with the skin fragility.
T393	163992-164068	Epistemic_statement	denotes	Collagen dysplasia has been described in many purebred and mixed-breed dogs.
T394	164316-164501	Epistemic_statement	denotes	Ocular abnormalities and joint laxity, associated problems commonly seen in humans with Ehlers-Danlos syndrome, have been reported infrequently in dogs, and bone abnormalities are rare.
T395	164637-164879	Epistemic_statement	denotes	The biochemical abnormality has not been identified in any cases of collagen dysplasia in dogs; but the skin of Springer Spaniels with is typical of dermatosparaxis of sheep and cattle and has also been described in a Himalayan cat and a dog.
T396	165005-165166	Epistemic_statement	denotes	They may all be uniformly larger or smaller, or there is a mixed population of fibrils that extend beyond the range of normal minimum and maximum diameter sizes.
T397	165756-165900	Epistemic_statement	denotes	For unknown reasons, the same biochemical defect may produce different clinical abnormalities in different individuals and in different species.
T398	166994-167177	Epistemic_statement	denotes	Dermatosparaxis in cattle is recessively inherited as is the biochemically analogous condition in humans, Ehlers-Danlos syndrome type VII C, although clinical signs are not identical.
T399	167274-167339	Epistemic_statement	denotes	Associated joint laxity and soft bones have been reported rarely.
T400	167534-167649	Epistemic_statement	denotes	Individual collagen fibers are smaller in diameter than in normal skin, and their arrangement appears disorganized.
T401	167650-167719	Epistemic_statement	denotes	There may be an increase in dermal elastin and number of fibroblasts.
T402	169233-169276	Epistemic_statement	denotes	There may be orthokeratotic hyperkeratosis.
T403	169277-169406	Epistemic_statement	denotes	The exact pathomechanism is unknown; however, it is thought to be related to an effect of glucocorticoids on collagen production.
T404	169407-169569	Epistemic_statement	denotes	In addition, many of the associated conditions have moderate to severe liver involvement, which suggests that hepatic dysfunction may play a role in pathogenesis.
T405	170027-170132	Epistemic_statement	denotes	An abnormality of dermal proteoglycan is a rarely documented cause of fragile skin in humans and animals.
T406	170494-170624	Epistemic_statement	denotes	However, levels of dermatan collagen dysplasia has been found to have more uncross-linked α-chains than collagen from normal dogs.
T407	170625-170751	Epistemic_statement	denotes	Histologic changes may be subtle and consist of dermal thinning evident only in comparison to a section from a normal control.
T408	170752-170957	Epistemic_statement	denotes	In other cases, a decreased amount of dermal collagen, collagen disorganization, variation in collagen staining, increased number of elastic fibers, or increased amount of extracellular matrix may be seen.
T409	170958-171022	Epistemic_statement	denotes	The abnormal collagen fibers may stain red with trichrome stain.
T410	171185-171249	Epistemic_statement	denotes	A mixture of normal and abnormal collagen fibers may be present.
T411	171250-171379	Epistemic_statement	denotes	Collagen dysplasia in cats is usually referred to as cutaneous asthenia, although in early reports it was called dermatosparaxis.
T412	171380-171544	Epistemic_statement	denotes	The condition has been reported in a number of breeds; in the majority of the cases, neither the biochemical defect nor the mode of inheritance has been identified.
T413	171730-171814	Epistemic_statement	denotes	This cat could not be bred, however, and the mode of inheritance was not determined.
T414	172790-172980	Epistemic_statement	denotes	Ultrastructural examination indicates that normal and abnormal collagen fibers may be present in of weeks, the lesions continue to expand and develop a dry, horny, papilloma-like appearance.
T415	173934-173991	Epistemic_statement	denotes	Coronary band changes, however, diminish as the pig ages.
T416	173992-174115	Epistemic_statement	denotes	At birth, affected piglets seem otherwise normal, but over a period of weeks they gradually decline in growth and vitality.
T417	174588-174631	Epistemic_statement	denotes	The mode of inheritance was not determined.
T418	174918-175056	Epistemic_statement	denotes	The hyaluronan accumulation is related to a higher expression of hyaluronan synthase 2 (HAS2) mRNA and HAS2 protein by dermal fibroblasts.
T419	175271-175375	Epistemic_statement	denotes	In some dogs, large lakes of mucin form nodules or cysts that may rupture and drip clear, stringy fluid.
T420	175809-175972	Epistemic_statement	denotes	Special stains can be used to better visualize the mucin; these include Alcian blue at pH 2.5, which stains mucin blue-green, and mucicarmine, which stains it red.
T421	176497-176620	Epistemic_statement	denotes	The economic impact of the disease may be considerable because virtually all homozygotes die before reaching slaughter age.
T422	176621-176781	Epistemic_statement	denotes	Skin lesions may be present at birth, but more commonly, they develop during the first 3 weeks of life, and in rare cases may not arise until 2-3 months of age.
T423	176909-176974	Epistemic_statement	denotes	They may extend up the sides and back but do not affect the head.
T424	178168-178335	Epistemic_statement	denotes	Basal keratinocytes are the only cells in the epidermis that can undergo mitosis, and once mitosis occurs, the basal cell proceeds to undergo terminal differentiation.
T425	178645-178704	Epistemic_statement	denotes	The intercellular and cell substrate adhesions are complex.
T426	178705-178910	Epistemic_statement	denotes	Hemidesmosomes and desmosomes are stable junctions that associate with cytoplasmic keratin filaments, whereas focal adhesions and adherens junctions connect to actin filaments and are transitory adhesions.
T427	179857-179973	Epistemic_statement	denotes	The molecular structure of keratin is very important, and genetic mutation(s) can affect keratin filament formation.
T428	180657-180826	Epistemic_statement	denotes	In chronic cases, epithelialization and interstitial fibrosis are evident, and multinucleated giant cells may be infrequent when the condition has lasted several months.
T429	180827-180893	Epistemic_statement	denotes	Typical pulmonary changes may be obscured by secondary infections.
T430	181341-181489	Epistemic_statement	denotes	Although present at birth, dermoid cysts are usually asymptomatic and may not be noticed until they become distended or infected in an older animal.
T431	181490-181652	Epistemic_statement	denotes	The cyst usually contains hair, keratin, and sebum, and this material may produce progressive enlargement of the structure so that it becomes clinically apparent.
T432	181822-182086	Epistemic_statement	denotes	In dogs, dermoid cysts have been reported most commonly in the Rhodesian Ridgeback, a breed in which the lesion appears to be inherited as a simple recessive trait; development of a cyst is predisposed to by a dominant mutation in 3 fibroblast growth factor genes.
T433	182150-182233	Epistemic_statement	denotes	It is unknown whether the lesion is an inherited condition in other breeds of dogs.
T434	182234-182367	Epistemic_statement	denotes	Dermoid cysts have been associated with multiple vertebral and spinal malformations and hindlimb neurologic deficits in several dogs.
T435	182368-182578	Epistemic_statement	denotes	The rare condition of nasal dermoid sinus cyst results in a discharging sinus over the external nares in dogs; the cyst may extend into the cranial vault and cause cerebral abscessation or recurrent meningitis.
T436	182690-182774	Epistemic_statement	denotes	Dermoid cysts are rare in cats, and both cases reported were in domestic shorthairs.
T437	182775-182815	Epistemic_statement	denotes	Dermoid cysts may be single or multiple.
T438	182967-183058	Epistemic_statement	denotes	A tuft of hair may protrude through this pore, and it may be surrounded by a whorl of hair.
T439	183059-183273	Epistemic_statement	denotes	The cyst may end blindly in the subcutis; it may connect to the dorsal spinous process of vertebrae directly or by a fibrous cord; or rarely, it extends down to be continuous with the dura mater of the spinal cord.
T440	184202-184410	Epistemic_statement	denotes	In the 1980s, this designation was potentially useful for treatment purposes, but it antedated the discovery of numerous hyperkeratotic conditions, with sebaceous adenitis and ichthyosis being prime examples.
T441	184587-184801	Epistemic_statement	denotes	Primary idiopathic seborrheic skin disease is reported in many breeds and has been suggested to have an inherited basis; however, the breed predilections and clinical lesions overlap those of allergic skin disease.
T442	185032-185228	Epistemic_statement	denotes	In Cocker Spaniels, cell proliferation kinetics indicate that seborrheic individuals have increased epithelial cell proliferation of the epidermis, hair follicle infundibulum, and sebaceous gland.
T443	185229-185379	Epistemic_statement	denotes	In addition, recombinant grafting studies have shown that the hyperproliferative epidermis from seborrheic Cocker Spaniels remains hyperproliferative.
T444	186069-186236	Epistemic_statement	denotes	In Labrador Retrievers, the distribution is often strikingly ventral ("water-line disease"), which in the current literature would be interpreted as atopic dermatitis.
T445	186237-186424	Epistemic_statement	denotes	Thus many cases that would have been called "primary seborrhea" in the past would now be classified as pyoderma, Malassezia dermatitis, sebaceous adenitis, allergic dermatitis, and so on.
T446	186425-186517	Epistemic_statement	denotes	Therefore "seborrhea" should be used only as a clinical descriptive, not an etiologic, term.
T447	186989-187093	Epistemic_statement	denotes	The parakeratosis is typically found overlying the shoulders of follicular ostia (parakeratotic "caps").
T448	187260-187347	Epistemic_statement	denotes	Spongiform or Munro's microabscesses may be seen in conjunction with the parakeratosis.
T449	188773-188863	Epistemic_statement	denotes	Keratinocytes forming the SC are dead and can be sloughed when desmosomes are broken down.
T450	188864-189053	Epistemic_statement	denotes	Hydrolytic enzymes, such as cathepsin B-like, carboxypeptidase, and acid phosphatase, are thought to be responsible for this desmosomal degradation and subsequent keratinocyte desquamation.
T451	189829-189946	Epistemic_statement	denotes	Seborrhea literally means "flow of sebum," and it has been loosely correlated with abnormal sebaceous gland function.
T452	190029-190161	Epistemic_statement	denotes	Scaling (i.e., seborrhea) is a common reaction of the skin to normalize a damaged skin barrier and can occur with almost any insult.
T453	190316-190427	Epistemic_statement	denotes	Acne is usually asymptomatic, although some cats may develop secondary bacterial folliculitis and furunculosis.
T454	190428-190540	Epistemic_statement	denotes	The clinical lesions appear on the chin and lips and include comedones, papules, alopecia, crusts, and erythema.
T455	190831-190908	Epistemic_statement	denotes	Either sex may be affected, and the condition usually develops early in life.
T456	190909-191019	Epistemic_statement	denotes	The disorder may represent a form of inherited follicular dysplasia or a follicular disorder of cornification.
T457	191223-191299	Epistemic_statement	denotes	Occasionally, secondary bacterial folliculitis and furunculosis may develop.
T458	191784-191898	Epistemic_statement	denotes	The enlargement is usually firm to slightly spongy, and associated with partial alopecia, scaling, and greasiness.
T459	192026-192164	Epistemic_statement	denotes	In most instances, canine tail gland hyperplasia is associated with hormonal imbalances, especially elevated levels of blood testosterone.
T460	192305-192458	Epistemic_statement	denotes	The entire dorsal surface of the tail in cats is replete with large, densely packed sebaceous glands, which are proposed to be embryonal hepatoid glands.
T461	192754-192937	Epistemic_statement	denotes	The cause of feline tail gland hyperplasia is unknown, and the colloquialism "stud tail" is misleading, as the condition is also seen in intact females and neutered males and females.
T462	193512-193652	Epistemic_statement	denotes	The cases may have subordinate patterns of suppurative folliculitis, furunculosis, perifolliculitis, and intraepidermal pustular dermatitis.
T463	193653-193761	Epistemic_statement	denotes	Primary seborrhea oleosa, presumably of autosomal recessive inheritance, has been described in Persian cats.
T464	194253-194304	Epistemic_statement	denotes	Generalized primary seborrhea is rare in the horse.
T465	194697-194825	Epistemic_statement	denotes	The etiology and pathogenesis are unknown, and aside from an association with puberty, there is little similarity to human acne.
T466	194826-194976	Epistemic_statement	denotes	The lesions are thought to develop from external hair follicle trauma (rubbing of face) that results in follicular inflammation and traumatic rupture.
T467	194977-195100	Epistemic_statement	denotes	The lesions consist of follicular papules and pustules on the chin and lips that may ulcerate and ooze suppurative exudate.
T468	195278-195363	Epistemic_statement	denotes	Early lesions may exhibit follicular keratosis, comedones, and variable inflammation.
T469	195755-195958	Epistemic_statement	denotes	The lesions are considered benign epidermal neoplasms and are occurs in aged dogs and is not associated with inflammation, although the development of fissures may lead to secondary bacterial infections.
T470	196273-196398	Epistemic_statement	denotes	Digital hyperkeratosis can occur as a congenital and presumed hereditary disorder in the Irish Terrier and Dogue de Bordeaux.
T471	196569-196638	Epistemic_statement	denotes	An autosomal mode of inheritance has been shown in the Irish Terrier.
T472	196639-196763	Epistemic_statement	denotes	This condition arises in Labradors Retrievers and their crosses at <1 year of age, and is thought to be autosomal recessive.
T473	197634-197707	Epistemic_statement	denotes	It occurs in many breeds; however, Quarter Horses seem to be predisposed.
T474	197996-198069	Epistemic_statement	denotes	The lesions are usually asymptomatic, and may be persistent or permanent.
T475	198070-198186	Epistemic_statement	denotes	The etiology of the condition is unknown but may involve an immune-mediated attack on the wall of the hair follicle.
T476	198187-198227	Epistemic_statement	denotes	The reason for the linearity is unknown.
T477	198386-198450	Epistemic_statement	denotes	Multinucleated giant cells and eosinophils are variably present.
T478	198451-198647	Epistemic_statement	denotes	Sebaceous glands can be secondarily effaced, and there is a variable amount of orthokeratotic or parakeratotic hyperkeratosis, with or without superficial perivascular nonsuppurative inflammation.
T479	198823-198932	Epistemic_statement	denotes	It represents a localized form of seborrheic dermatosis, can occur at any age, and has no breed predilection.
T480	199420-199493	Epistemic_statement	denotes	The base of the horn must be inspected for the possible underlying cause.
T481	199868-200112	Epistemic_statement	denotes	The term nevus implies a lesion present at birth and composed of mature elements, and therefore, because these linear hyperkeratotic lesions have in common an early age of onset, they may represent linear epidermal nevi that have tardive onset.
T482	200113-200339	Epistemic_statement	denotes	Equine cannon keratosis is grossly and histologically similar to linear epidermal nevi but differs from the linear epidermal nevi of Belgian horses, as it can occur at any age, and is restricted to the skin of the cannon area.
T483	200462-200655	Epistemic_statement	denotes	The condition has been reported in more than 50 breeds of dogs and in mongrels; however, there are breed predilections for the Standard Poodle, Akita, Samoyed, Vizsla, Lhasa Apso, and Havanese.
T484	200656-200729	Epistemic_statement	denotes	In Standard Poodles and Akitas, an autosomal recessive trait is proposed.
T485	200802-200916	Epistemic_statement	denotes	There appears to be a slight sex predilection for males in Standard Poodles, Havanese dogs, and Springer Spaniels.
T486	200917-201007	Epistemic_statement	denotes	very common in humans but rarely diagnosed in middle age to older dogs (mean age 9 years).
T487	201008-201091	Epistemic_statement	denotes	They are of unknown cause, and have nothing to do with the clinical term seborrhea.
T488	201092-201185	Epistemic_statement	denotes	The lesions may be single or multiple and have no apparent breed, sex, or site predilections.
T489	201495-201682	Epistemic_statement	denotes	This proliferation of monomorphic basaloid keratinocytes undergoes abrupt cornification and surrounds impacted, hyperkeratotic follicular ostia, which may develop into keratin horn-cysts.
T490	201683-201820	Epistemic_statement	denotes	The lesions can be confused with viral plaques and are distinguished by the lack of hypergranulosis and papillomavirus cytopathic effect.
T491	201821-201935	Epistemic_statement	denotes	In humans, the sudden appearance or enlargement of multiple lesions can be associated with an internal malignancy.
T492	201936-201991	Epistemic_statement	denotes	This association has not been made in domestic animals.
T493	201992-202179	Epistemic_statement	denotes	Lichenoid keratoses have been reported as single or occasionally multiple wart-like papules or hyperkeratotic plaques that may be hyperpigmented on the inner surface of the pinna in dogs.
T494	202180-202234	Epistemic_statement	denotes	Age, breed, and sex predilections have not been noted.
T495	202501-202817	Epistemic_statement	denotes	Lichenoid reaction patterns in dogs, and rarely cats, may correspond to specific diseases (e.g., uveodermatologic syndrome, discoid lupus), but an idiopathic lichenoid reaction (lichenoid dermatosis) is occasionally seen in dogs and may represent a poorly characterized form of chronic cutaneous lupus erythematosus.
T496	202818-203036	Epistemic_statement	denotes	Idiopathic lichenoid dermatosis is characterized by usually asymptomatic, symmetrical, grouped, flattopped papules and plaques that are variably distributed, and that develop a scaly to markedly hyperkeratotic surface.
T497	203037-203130	Epistemic_statement	denotes	The lesions have been described as self-limiting, although resolution may take several years.
T498	203357-203514	Epistemic_statement	denotes	Apoptotic keratinocytes can be seen primarily, although not exclusively, in the basal layer, and there is often hydropic degeneration of basal keratinocytes.
T499	203515-203698	Epistemic_statement	denotes	If focal areas of suppurative epidermitis and/or suppurative luminal folliculitis are present, a lichenoid tissue reaction in response to staphylococcal infection should be suspected.
T500	203699-203837	Epistemic_statement	denotes	A lichenoid psoriasiform dermatosis may occur in dogs on long-standing oral cyclosporine for refractory allergic skin or other conditions.

T1

1568-1620

Epistemic_statement

denotes

To interpret skin biopsies, pathologists must have a

T2

1621-1706

Epistemic_statement

denotes

We gratefully acknowledge the contributions to prior editions of this chapter by Drs.

T3

2387-2487

Epistemic_statement

denotes

In addition to causing undo suffering, severe skin disease may interfere with the human-animal bond.

T4

2644-2795

Epistemic_statement

denotes

The protective barrier of the skin is complex, and much of this function is provided by the stratum corneum (SC), the outermost layer of the epidermis.

T5

3058-3160

Epistemic_statement

denotes

They have a complex structure that includes cadherin proteins of 2 types-desmocollins and desmogleins.

T6

3909-4019

Epistemic_statement

denotes

This layer is much thicker in nonhaired skin and may be up to 20 cells thick in the footpads and nasal planum.

T7

4020-4134

Epistemic_statement

denotes

• The stratum granulosum is variably apparent on light microscopy in haired skin and appears only 1-2 cells thick.

T8

5298-5429

Epistemic_statement

denotes

In doing so, keratinocytes must lose a large amount of water volume (from 70% water in nucleated layers to 15% in stratum corneum).

T9

5430-5565

Epistemic_statement

denotes

Minor injuries to the corneal layer from tape stripping or applications of solvents will result in increased transepidermal water loss.

T10

5566-5828

Epistemic_statement

denotes

Several steps must occur for cornification to proceed normally: (1) bundling of keratin to establish the corneocyte core, (2) replacement of the cell membrane with a thick cornified envelope, (3) formation of lipid lamellar bilayers, and (4) active desquamation.

T11

5829-5930

Epistemic_statement

denotes

Alterations in any step can lead to hyperkeratosis, clinical scaling, and decreased barrier function.

T12

6581-6806

Epistemic_statement

denotes

Although the architecture of the skin is conserved across most mammalian species, the pathologist must be aware of differences between species and site differences within the same species, to interpret normal versus abnormal.

T13

9039-9153

Epistemic_statement

denotes

Commitment to differentiation in suprabasal keratinocytes is associated with induction of keratins 1 (K1) and K10.

T14

10883-11043

Epistemic_statement

denotes

There has been a long-standing debate over whether Merkel cells originate from epidermal or neural stem cells, but current studies indicate an epidermal origin.

T15

11663-11856

Epistemic_statement

denotes

Merkel cells form Merkel cell-neurite complexes with axons in tylotrich pads and sinus hairs that are thought to function as gentle touch receptors that initiate slow-adapting type 1 responses.

T16

11857-12051

Epistemic_statement

denotes

Their exact function in these structures is uncertain, but they are thought not to act as sensory cells but rather to function as abutments for deformation of the mechanosensitive nerve endings.

T17

12052-12169

Epistemic_statement

denotes

Merkel cells are also thought to have various neuroendocrine effects and to be involved in control of the hair cycle.

T18

12170-12291

Epistemic_statement

denotes

The basement membrane zone (BMZ) is the structurally and biochemically complex junction between the epidermis and dermis.

T19

12846-13001

Epistemic_statement

denotes

The BMZ has a crucial role in anchoring the epidermis to the dermis, and abnormalities of the BMZ result in serious and potentially fatal bullous diseases.

T20

13002-13160

Epistemic_statement

denotes

The BMZ also influences growth and differentiation of keratinocytes and acts as a selective barrier for passage of molecules between the epidermis and dermis.

T21

14855-15093

Epistemic_statement

denotes

Melanocytes are located in the basal layer of the epidermis and outer root sheath of hair follicles; and in hematoxylin and eosin (H&E) sections, they appear as clear cells with a small dark-staining nucleus because of shrinkage artifact.

T22

15141-15196

Epistemic_statement

denotes

The dendritic processes can be seen with silver stains.

T23

15719-15848

Epistemic_statement

denotes

Most melanin pigment in skin is in the basal layer, but in dark-skinned animals, melanin may be present throughout the epidermis.

T24

16407-16574

Epistemic_statement

denotes

They appear as clear cells on routine H&E sections and may be distributed from the stratum basale to the stratum spinosum, depending on species and region of the skin.

T25

16575-16632

Epistemic_statement

denotes

They are usually less numerous than melanocytes, however.

T26

17170-17344

Epistemic_statement

denotes

The ground substance is usually not visible in normal H&E sections; however, a fine granular to fibrillar basophilic material is occasionally evident between collagen fibers.

T27

18250-18352

Epistemic_statement

denotes

The skin is supplied with sensory and autonomic nerves that are usually associated with blood vessels.

T28

20142-20270

Epistemic_statement

denotes

SCF is thought to home mast cells to the dermis as well as regulate the synthesis of mast cell mediators and secretory function.

T29

20608-20920

Epistemic_statement

denotes

Degranulation of both canine and human mast cells is thought to involve breakdown of their secretory granules located on the basal aspect of basal keratinocytes, and they consist of a cytoplasmic plaque that connects to the cytoskeleton and a transmembrane portion that binds to the underlying basement membrane.

T30

24305-24484

Epistemic_statement

denotes

Fibronectins are glycopro-has been suggested as a more appropriate term to encompass the skin-specific immune response-associated cells and humoral factors present in normal skin.

T31

24819-24972

Epistemic_statement

denotes

• Langerhans cells are thought to trap antigens in the epidermis, migrate out to regional lymph nodes via lymphatics, and present the antigen to T cells.

T32

25636-25840

Epistemic_statement

denotes

• E-selectin is thought to act as an adhesion molecule or vascular addressin for a specific subset of skin-homing memory T cells, which have the ligand cutaneous lymphocyte antigen (CLA) on their surface.

T33

25983-26241

Epistemic_statement

denotes

Thus it appears that the proinflammatory, upregulating effects of keratinocytes prepare the dermis for specific immunologic activity, whereas migrating antigen-presenting Langerhans cells induce expansion of specific lymphocytes in skin-draining lymph nodes.

T34

26609-26737

Epistemic_statement

denotes

In general, however, hair follicle density is greatest over the dorsolateral aspect of the body and least on the ventral aspect.

T35

26817-26995

Epistemic_statement

denotes

Primary hairs have a large diameter, are rooted more deeply in the dermis or subcutis, and are associated with sebaceous and epitrichial sweat glands and an arrector pili muscle.

T36

26996-27169

Epistemic_statement

denotes

Secondary hair follicles are smaller in diameter, are more superficially rooted, and may be accompanied by a sebaceous gland but lack a sweat gland and arrector pili muscle.

T37

28341-28576

Epistemic_statement

denotes

A subpopulation of mast cells that does not exhibit metachromasia following formalin fixation has been demonstrated in the skin of dogs and cattle, and heterogeneity of protein content has been identified in dermal mast cells of sheep.

T38

29123-29413

Epistemic_statement

denotes

Mast cells also function in persistent chronic inflammatory reactions, tissue repair and remodeling, pathologic fibrosis, angiogenesis, hemostasis, hematopoiesis, antibody production, protection against bacterial infections, response to neoplasms, and possibly in control of the hair cycle.

T39

29901-29991

Epistemic_statement

denotes

Contraction of arrector pili muscles may also be involved in emptying of sebaceous glands.

T40

30075-30138

Epistemic_statement

denotes

They may be vacuolated in normal animals, especially aged dogs.

T41

30429-30485

Epistemic_statement

denotes

The functional significance of this muscle is uncertain.

T42

30486-30572

Epistemic_statement

denotes

Skeletal muscles may be present in the muzzle, forehead, eyelid, and perianal regions.

T43

30705-30787

Epistemic_statement

denotes

Skeletal muscle fibers also are associated with the large sinus hairs of the face.

T44

30788-31120

Epistemic_statement

denotes

The skin has been proposed to function as an immunosurveillance organ, and the term skin-associated lymphoid tissue (SALT), analogous to gut-associated and bronchial-associated lymphoid tissues (GALT, BALT) , has been suggested to describe those cellular elements of the skin that deal with antigenic challenges at the skin surface.

T45

31121-31269

Epistemic_statement

denotes

However, this concept has been disputed because of presumed differences in immune function between the common mucosal immune system and normal skin.

T46

31270-31410

Epistemic_statement

denotes

The alternative name, skin immune system (SIS), activity is thought to be an adaptive response to seasonal variation in ambient temperature.

T47

31647-31728

Epistemic_statement

denotes

The hair cycle in the remaining follicles could not be assigned a specific stage.

T48

33142-33388

Epistemic_statement

denotes

In rodents, the bulge region of the follicle appears to be the site that contains slowcycling relatively undifferentiated cells from which arise a population of transient amplifying cells that become the matrix keratinocytes of the new hair bulb.

T49

33678-33831

Epistemic_statement

denotes

Hair growth in many animals has been shown to be regulated by photoperiod, ambient temperature, various hormones, nutritional status, and general health.

T50

33832-33913

Epistemic_statement

denotes

However, the exact mechanisms that control the cycle are incompletely understood.

T51

34327-34467

Epistemic_statement

denotes

Factors from the papilla mesenchymal cells are thought to act on a stem cell population in the permanent upper portion of the hair follicle.

T52

34608-34763

Epistemic_statement

denotes

Transition between anagen and catagen appears to be regulated by The histologic appearance of the hair follicle changes considerably during the hair cycle.

T53

35233-35334

Epistemic_statement

denotes

Goats have primary follicles in groups of 3, with 3-6 secondary follicles associated with each group.

T54

35539-35603

Epistemic_statement

denotes

As many as 15 hairs may emerge from a single follicular orifice.

T55

36283-36857

Epistemic_statement

denotes

In longitudinal section, the fully developed hair follicle consists of 3 segments: • The lower or inferior portion, from the base of the follicle to the point of insertion of the arrector pili muscle • The isthmus, the short section from the attachment of the arrector pili muscle to the entrance of the sebaceous duct • The infundibulum, extending from the entrance of the sebaceous duct to the follicular orifice The inferior segment can be considered temporary because it disappears during the involution stage of the hair cycle and reforms again during the active phase.

T56

39326-39483

Epistemic_statement

denotes

They are usually largest in areas with lowest hair follicle density, such as mucocutaneous junctions, interdigital spaces, coronet, and dorsal neck and rump.

T57

39731-39875

Epistemic_statement

denotes

The footpads and nasal planum are devoid of sebaceous glands, and they are rare in glabrous skin, where they empty directly to the skin surface.

T58

40162-40307

Epistemic_statement

denotes

The anal sacs are squamous epithelial-lined cystic cavities containing odoriferous secretions, presumably with some territorial marking function.

T59

41031-41114

Epistemic_statement

denotes

Larger ducts, lined by stratified squamous epithelium, may be evident in neoplasms.

T60

41115-41221

Epistemic_statement

denotes

These ducts are thought to regress during embryonal development, which leaves the glands largely ductless.

T61

41309-41442

Epistemic_statement

denotes

Their function is uncertain, but they may have a role in steroid metabolism, in production of pheromones, and in territorial marking.

T62

41585-41722

Epistemic_statement

denotes

Two types of sweat glands are present in the skin of mammals; they differ in origin, distribution, and possibly in the mode of secretion.

T63

41723-41982

Epistemic_statement

denotes

These glands have been called apocrine and eccrine glands, but because of questions concerning the mechanism of the secretory process of these glands, the names epitrichial and atrichial glands have been proposed for apocrine and eccrine glands, respectively.

T64

42158-42459

Epistemic_statement

denotes

Epitrichial glands are associated with primary hair follicles only, and they tend to be largest in areas with lower hair follicle density, such as mucocutaneous junctions, interdigital follicles have a well-developed, flame-shaped, plump dermal papilla (DP) that is capped completely by the hair bulb.

T65

42688-42867

Epistemic_statement

denotes

Catagen, the intermediate remodeling stage, is short-lived and very difficult to assess on routine histology as it requires a perfectly sectioned follicle in a longitudinal plane.

T66

43432-43617

Epistemic_statement

denotes

Telogen may be further described as "haired telogen," which has retention of the hair shaft, and "hairless telogen" or "kenogen," in which a telogen follicle rests without a hair shaft.

T67

45334-45511

Epistemic_statement

denotes

Sebaceous glands also appear to be involved with normal hair development, because, in the absence of sebaceous glands, the hair shaft fails to separate normally from the sheath.

T68

46173-46270

Epistemic_statement

denotes

In other species, the secretion may contribute to scent that is involved in social communication.

T69

46271-46413

Epistemic_statement

denotes

Epitrichial secretion may also provide a means of excreting waste products and secreting immunoglobulins that are present on the skin surface.

T70

46711-46841

Epistemic_statement

denotes

The duct empties into the pilary canal, usually above the entrance of the sebaceous duct or, rarely, directly to the skin surface.

T71

46842-46983

Epistemic_statement

denotes

The name apocrine refers to the mode of secretion, which was originally thought to involve pinching off (apo = off) of a portion of the cell.

T72

46984-47223

Epistemic_statement

denotes

The existence of an apocrine secretory process has been questioned; however, ultrastructural examination of these glands in humans, pigs, horses, and dogs indicates that several modes of secretion are involved, including the apocrine type.

T73

47586-47630

Epistemic_statement

denotes

The function of eccrine glands is uncertain.

T74

47631-47757

Epistemic_statement

denotes

The secretion may be involved with scent signaling, and in the footpad of cats, it may improve frictional capacity of the paw.

T75

48285-48310

Epistemic_statement

denotes

granulomas may be formed.

T76

48311-48461

Epistemic_statement

denotes

Flame figures may be seen in eosinophilic granuloma, insect-/arthropod-bite reactions, and other eosinophil-rich conditions, such as mast cell tumors.

T77

48835-49013

Epistemic_statement

denotes

Crusts should be examined closely for dermatophyte spores and hyphae, Dermatophilus congolensis, and acantholytic keratinocytes, which can be indicators of superficial pemphigus.

T78

49249-49399

Epistemic_statement

denotes

The dilated lymphatics and widened perivascular and interstitial spaces may or may not contain lightly eosinophilic, homogeneous, proteinaceous fluid.

T79

49465-49700

Epistemic_statement

denotes

Severe edema of the superficial dermis may result in subepidermal vesicles and bullae, necrosis of the overlying epidermis, and predisposition to artifactual dermoepidermal separation during handling and processing of biopsy specimens.

T80

49701-49887

Epistemic_statement

denotes

Severe edema of the superficial dermis may result in vertical orientation and stretching of collagen fibers, producing the "gossamer" (web-like) collagen effect seen in severe urticaria.

T81

50214-50348

Epistemic_statement

denotes

Dyskeratosis may be seen in a number of dermatoses, including lupus erythematosus, erythema multiforme, and graft-versus-host disease.

T82

50349-50415

Epistemic_statement

denotes

It can also occur in neoplastic dermatoses, especially papillomas.

T83

50655-50755

Epistemic_statement

denotes

It is an abnormal but nonneoplastic change; however, it can accompany or precede neoplastic changes.

T84

50912-51112

Epistemic_statement

denotes

Dystrophic mineralization of the hair follicle basement membrane can be seen in hyperglucocorticism, in dogs receiving exogenous glucocorticoids, and as a senile change in dogs, especially in Poodles.

T85

51206-51496

Epistemic_statement

denotes

They are found within the epidermis as well as the hair follicle outer root sheath, and are most commonly found in diseases associated with tissue eosinophilia, such as feline eosinophilic plaque and feline eosinophilic granuloma, and thus are associated with allergic skin disease in cats.

T86

51703-51960

Epistemic_statement

denotes

Exocytosis of neutrophils implies an infectious process, whereas exocytosis of eosinophils suggests a hypersensitivity reaction, such as ectoparasitism and feline Dermal atrophy is thinning of dermal collagen fibrils resulting in decreased dermal thickness.

T87

52423-52500

Epistemic_statement

denotes

Clefts may be caused by acantholysis or hydropic degeneration of basal cells.

T88

52501-52562

Epistemic_statement

denotes

However, clefts may also result from handling artifacts (Fig.

T89

53214-53316

Epistemic_statement

denotes

Festoons can be seen in mechanobullous disorders, such as epidermolysis bullosa or bullous pemphigoid.

T90

53481-53605

Epistemic_statement

denotes

The fibrinoid change results in loss of structural detail and may be accompanied by necrotic cell debris or leukocytoclasia.

T91

53859-54035

Epistemic_statement

denotes

These can be seen in endocrinopathies, hair cycle arrest, and are also prominent in normal haired skin of plush-coated breeds of dog, such as the Nordic breeds and Pomeranians.

T92

54473-54572

Epistemic_statement

denotes

It can further be divided into mural folliculitis (inflammation of the follicular epithelium) (Fig.

T93

54956-55097

Epistemic_statement

denotes

This can be seen in any process that is destructive to hair follicles, such as bacterial infection, dermatophytosis, demodicosis, and trauma.

T94

56067-56226

Epistemic_statement

denotes

By definition, hamartomas are congenital lesions; however, they may not be detected until later in life, and the term is often used interchangeably with nevus.

T95

56372-56528

Epistemic_statement

denotes

Hamartoma is the term preferred in veterinary dermatopathology; however, there are a few conditions where "nevus" is ingrained in the veterinary literature.

T96

57673-57759

Epistemic_statement

denotes

Hypergranulosis may be seen in any dermatosis in which there is epidermal hyperplasia.

T97

57829-57921

Epistemic_statement

denotes

It can be either orthokeratotic (without nuclei) , or parakeratotic (nuclei retained) ( Fig.

T98

57997-58113

Epistemic_statement

denotes

Orthokeratosis can be divided into basket weave (the normal pattern in the stratum corneum), compact, and laminated.

T99

58518-58691

Epistemic_statement

denotes

Diffuse parakeratosis can be seen in many chronic dermatoses, especially zinc-responsive dermatosis, dermatophilosis, superficial necrolytic dermatitis, and thallotoxicosis.

T100

58808-58929

Epistemic_statement

denotes

Hyperpigmentation may be focal or diffuse, and confined to the stratum basale or present throughout all epidermal layers.

T101

59075-59176

Epistemic_statement

denotes

Hyperpigmentation must always be cautiously assessed with regard to the animal's normal pigmentation.

T102

59472-59920

Epistemic_statement

denotes

Epidermal hyperplasia may be further specified as irregular (in which the hyperplastic rete ridges are uneven in shape and height), regular or psoriasiform (in which the hyperplastic rete ridges are of even thickness and length), papillated (digitate projections of the epidermis above the skin surface), and pseudocarcinomatous (extreme, irregular hyperplasia that may demonstrate increased mitotic activity and branched or fused rete pegs) ( Fig.

T103

59928-60057

Epistemic_statement

denotes

The process may resemble squamous cell carcinoma; however, there is no cellular atypia, and the basement membrane remains intact.

T104

60121-60529

Epistemic_statement

denotes

It may be associated with congenital or acquired idiopathic defects in melanization (leukoderma, vitiligo), toxic effects of certain chemicals on melanocytes (e.g., mono benzylether of dihydroquinone in rubbers and plastics), inflammatory disorders that affect melanization or destroy melanocytes, hormonal disorders, and dermatoses featuring hydropic degeneration of basal cells (e.g., lupus erythematosus).

T105

60706-60838

Epistemic_statement

denotes

Intracellular edema of the epidermis may affect cells in a laminar fashion, leading to horizontal layers of edematous keratinocytes.

T106

60839-60931

Epistemic_statement

denotes

Severe intracellular edema may result in reticular degeneration and intraepidermal vesicles.

T107

61184-61323

Epistemic_statement

denotes

Hydropic degeneration may result in intrabasal clefts or vesicles, or subepidermal clefts or vesicles because of dermoepidermal separation.

T108

62060-62243

Epistemic_statement

denotes

They are seen most frequently in conjunction with immune-mediated dermatoses, dermatoses associated with tissue eosinophilia, and in panniculitis, such as injection-site panniculitis.

T109

62309-62598

Epistemic_statement

denotes

Mucinosis (myxedema, myxoid degeneration, mucoid degeneration) is an accumulation of dermal ground substance that appears as slightly granular, basophilic material that separates, thins, or replaces dermal collagen fibers and surrounds blood vessels and appendages in H&E-stained sections.

T110

63028-63128

Epistemic_statement

denotes

It may be seen with any acute or subacute inflammatory dermatosis, such as acute contact dermatitis.

T111

64286-64412

Epistemic_statement

denotes

Severe intercellular edema may lead to rupture of the intercellular bridges and the formation of intraepidermal vesicles (Fig.

T112

64422-64542

Epistemic_statement

denotes

Severe spongiotic vesicle formation may disrupt the basement membrane zone in some areas and form subepidermal vesicles.

T113

64629-64801

Epistemic_statement

denotes

Diffuse spongiosis, which also involves the hair follicle outer root sheath, may be seen in other inflammatory disorders, including feline eosinophilic plaque or granuloma.

T114

65108-65228

Epistemic_statement

denotes

Mucinous degeneration may be seen as a focal process in numerous inflammatory, neoplastic, and developmental dermatoses.

T115

65304-65455

Epistemic_statement

denotes

Multinucleated keratinocytes can occasionally be seen in infections by viruses, such as herpesvirus, canine distemper virus, and feline leukemia virus.

T116

65879-65994

Epistemic_statement

denotes

Apoptosis is often used synonymously with individual keratinocyte death that may occur from a variety of processes.

T117

65995-66114

Epistemic_statement

denotes

Individual keratinocyte necrosis can occur in erythema multiforme, graft-versus-host disease, and interface dermatoses.

T118

66115-66250

Epistemic_statement

denotes

Necrosis of the epidermis or dermis may be more extensive due to physical and chemical injury, or to interference with vascular supply.

T119

66484-66697

Epistemic_statement

denotes

It can occur without significant involvement of the overlying dermis and epidermis (e.g., sterile nodular panniculitis, feline nutritional steatitis), or can be involved by extension of inflammation of the dermis.

T120

66698-66871

Epistemic_statement

denotes

Fat micropseudocyst formation and lipocytes containing radially arranged needleshaped clefts can be seen with subcutaneous fat sclerosis and idiopathic sterile panniculitis.

T121

67045-67165

Epistemic_statement

denotes

Papillomatosis is associated with epidermal hyperplasia and is seen with chronic inflammatory and neoplastic dermatoses.

T122

67479-67510

Epistemic_statement

denotes

It can result from any process

T123

67511-67642

Epistemic_statement

denotes

Used commonly in the diagnoses of neoplasms, a system of pattern analysis is also applied to inflammatory/nonneoplastic dermatoses.

T124

67643-67738

Epistemic_statement

denotes

Most dermatologic lesions can be grouped into 1 of 10 histologic patterns on low magnification.

T125

68772-68850

Epistemic_statement

denotes

It can be difficult to gauge the importance of each pattern within the biopsy.

T126

68851-69002

Epistemic_statement

denotes

Some patterns are more specific than Transepidermal elimination is a mechanism by which foreign or altered constituents can be removed from the dermis.

T127

69003-69137

Epistemic_statement

denotes

This can be illustrated by the elimination of mineralized collagen across the epidermis and follicular epithelium in calcinosis cutis.

T128

69193-69280

Epistemic_statement

denotes

They may be subcorneal, suprabasilar, subepidermal, or immediately below the epidermis.

T129

69281-69387

Epistemic_statement

denotes

When these lesions contain large numbers of inflammatory cells, they may be referred to as vesicopustules.

T130

69653-69923

Epistemic_statement

denotes

They may be caused by severe intercellular or intracellular edema, ballooning degeneration, acantholysis, hydropic degeneration of basal cells, subepidermal edema, or other factors resulting in dermoepidermal separation, such as the autoantibodies in bullous pemphigoid.

T131

70404-70510

Epistemic_statement

denotes

Severe spongiotic vesiculation may disrupt the basement membrane zone, resulting in subepidermal vesicles.

T132

70788-70961

Epistemic_statement

denotes

When the hair follicle outer root sheath is also involved, feline allergic dermatitides, such as feline eosinophilic plaque and feline eosinophilic granuloma, are suggested.

T133

70962-71124

Epistemic_statement

denotes

• Perivascular dermatitis with epidermal hyperplasia is characterized by various degrees of epidermal hyperplasia and hyperkeratosis with little or no spongiosis.

T134

71485-71615

Epistemic_statement

denotes

The presence of parakeratosis suggests zincresponsive dermatosis, chronic ectoparasite hypersensitivity, or Malassezia dermatitis.

T135

71805-72016

Epistemic_statement

denotes

This pattern can be divided into interface cell poor (interface changes with minimal superficial dermal inflammation) or interface lichenoid (interface changes with a lichenoid band of mononuclear inflammation).

T136

72095-72326

Epistemic_statement

denotes

• The cell-poor interface pattern can be seen in diseases such as dermatomyositis, ischemic dermatopathy, erythema multiforme, drug eruptions, graft-versus-host reactions, bovine viral diarrhea, and bovine pseudolumpy skin disease.

T137

72976-73084

Epistemic_statement

denotes

Caution should be exercised in differentiating interface lichenoid inflammation from lichenoid inflammation.

T138

74133-74407

Epistemic_statement

denotes

The primary cause of superficial perivascular dermatitis is a hypersensitivity reaction, although chronic bacterial infections, viral infections, cornification disorders, and metabolic disease can all demonstrate this pattern at some point during evolution of the condition.

T139

74408-74557

Epistemic_statement

denotes

Perivascular infiltrates containing eosinophils should first be suspected of representing dermatitis, such as ectoparasitism, food allergy, or atopy.

T140

74558-74665

Epistemic_statement

denotes

Focal areas of eosinophilic exocytosis and necrosis ("epidermal nibbles") are suggestive of ectoparasitism.

T141

74666-74843

Epistemic_statement

denotes

Other perivascular dermatitides that may contain eosinophils include zinc-responsive dermatosis, equine multisystemic eosinophilic epitheliotropic disease, and chronic pyoderma.

T142

75131-75160

Epistemic_statement

denotes

rarely in cutaneous lymphoma.

T143

75161-75246

Epistemic_statement

denotes

It can also reflect a chronic stage of a vasculitis that was originally neutrophilic.

T144

75247-75281

Epistemic_statement

denotes

• Eosinophilic vasculitis is rare.

T145

75282-75537

Epistemic_statement

denotes

It is seen most commonly in lesions induced by arthropod insult, drug eruptions, food hypersensitivity, equine axillary nodular necrosis, idiopathic nodular eosinophilic vasculitis in horses, feline eosinophilic granulomas, and rarely in mast cell tumors.

T146

75695-75848

Epistemic_statement

denotes

Nodular and diffuse dermatitis may be characterized by the predominant cell type present (neutrophils, macrophages, lymphocytes, eosinophils, or mixed) .

T147

75849-75960

Epistemic_statement

denotes

The inciting antigen may be an infectious agent, noninfectious material, or the inflammation may be idiopathic.

T148

75961-76084

Epistemic_statement

denotes

Neutrophils predominate in dermal abscesses associated with infectious agents such as bacteria, fungi, algae, and protozoa.

T149

76571-76665

Epistemic_statement

denotes

It can be accompanied by fibrinoid necrosis, thrombosis, hemorrhage, and evidence of ischemia.

T150

76666-76710

Epistemic_statement

denotes

Vasculitis can be immune mediated or septic.

T151

77193-77280

Epistemic_statement

denotes

Vasculitis can also be locally induced by bacterial antigens deposited in vessel walls.

T152

77281-77385

Epistemic_statement

denotes

Vasculitis can further be classified on the basis of the dominant inflammatory cell within vessel walls.

T153

77454-77595

Epistemic_statement

denotes

It should be noted that the inflammatory cell involved often reflects the stage of the disease rather than characterizing a specific disease.

T154

77596-77778

Epistemic_statement

denotes

• Neutrophilic vasculitis is by far the most common type and may be leukocytoclastic (associated with karyorrhexis of neutrophils resulting in "nuclear dust") or nonleukocytoclastic.

T155

77995-78190

Epistemic_statement

denotes

• Lymphocytic vasculitis may be seen with dermatomyositis, malignant catarrhal fever, vaccine-induced panniculitis, and dant finely granular, eosinophilic cytoplasm with ill-defined cell borders.

T156

78575-78780

Epistemic_statement

denotes

In general, these 3 forms of giant cells have little diagnostic specificity, although the Touton variety is strongly indicative of xanthomas, and the Langhans type suggests the need for an acid-fast stain.

T157

78781-79022

Epistemic_statement

denotes

Eosinophils may predominate in feline, canine, and equine eosinophilic granuloma; in certain parasitic dermatoses (habronemiasis, elaeophoriasis, parafilariasis, dirofilariasis, dracunculiasis); in furunculosis, and in hairy vetch toxicosis.

T158

79346-79436

Epistemic_statement

denotes

They may contain eosinophilic, intracytoplasmic inclusions that are called Russell bodies.

T159

79437-79547

Epistemic_statement

denotes

These accumulations of glycoprotein are largely globulin and may be large enough to displace the cell nucleus.

T160

79548-79752

Epistemic_statement

denotes

Reactions to ruptured hair follicles are a common cause of nodular and diffuse pyogranulomatous dermatitis in domestic animals, and any such lesion should be examined for keratinous and epithelial debris.

T161

79753-79901

Epistemic_statement

denotes

All other nodular and diffuse dermatitides should be cultured, examined in polarized light for foreign material, and stained for bacteria and fungi.

T162

79902-79996

Epistemic_statement

denotes

In general, microorganisms are most likely to be found near areas of suppuration and necrosis.

T163

79997-80209

Epistemic_statement

denotes

Intraepidermal vesicles and pustules can be caused by intercellular edema that can be seen in any acute or subacute dermatosis, viral infections, hydropic degeneration of keratinocytes, and by acantholysis ( Fig.

T164

80218-80334

Epistemic_statement

denotes

It can be useful to subdivide this category on the basis of the site of the vesicle or pustule within the epidermis.

T165

80335-80524

Epistemic_statement

denotes

• Subcorneal pustules and vesicles are most commonly seen in pemphigus foliaceus, pustules associated with superficial pyoderma, and eosinophilic pustules resulting from hypersensitivities.

T166

80758-80914

Epistemic_statement

denotes

• Intrabasilar vesicles can be seen in lupus erythematosus, dermatomyositis, erythema multiforme, graft-versus-host disease, and toxic epidermal necrolysis.

T167

81006-81261

Epistemic_statement

denotes

Subepidermal vesicles and pustules may be formed through hydropic degeneration of basal cells, dermoepidermal separation, severe subepidermal edema and/or cellular infiltration, and severe intercellular edema with disruption of the basement membrane zone.

T168

81262-81478

Epistemic_statement

denotes

Caution is warranted when examining older lesions, as re-epithelialization may result in subepidermal vesicles and pustules assuming an intraepidermal location as re-epithelialization forms a pseudobase to a vesicle.

T169

81762-81971

Epistemic_statement

denotes

Ulcers limited to the upper portion of the superficial dermis do not usually result in scarring, whereas virtually all ulcers that extend into the deep dermis result in fibrosis and clinical signs of scarring.

T170

82385-82466

Epistemic_statement

denotes

Likewise, the panniculus can be secondarily involved in deep dermal inflammation.

T171

82467-82820

Epistemic_statement

denotes

Panniculitis may be caused by infectious agents, foreign bodies, vitamin E deficiency, trauma, pancreatic nant), orthokeratotic hyperkeratosis, follicular keratosis, decreased numbers of hair shafts in follicular infundibula, epidermal atrophy, sebaceous gland atrophy, and dermal atrophy (this can be difficult to assess without site-matched controls).

T172

82821-83002

Epistemic_statement

denotes

Atrophic dermatosis is rarely diagnostic for a specific condition but can suggest a group of diseases such as the endocrine dermatoses, the most common cause of atrophic dermatosis.

T173

83003-83114

Epistemic_statement

denotes

It will almost always be necessary to confirm the identity of the endocrinopathy with endocrine function tests.

T174

83115-83311

Epistemic_statement

denotes

Other causes of atrophic dermatoses include ischemia, feline acquired skin fragility, and alopecia X. Follicular and adnexal atrophy can also be secondary, rather than the primary disease process.

T175

83736-83780

Epistemic_statement

denotes

However, it is often sterile and idiopathic.

T176

83781-83979

Epistemic_statement

denotes

Panniculitis can be divided into lobular (fat lobules are primarily involved), septal (interlobular connective tissue septa are primarily involved), and diffuse (both anatomic areas involved) types.

T177

83980-84036

Epistemic_statement

denotes

Septal panniculitis is often associated with vasculitis.

T178

84037-84114

Epistemic_statement

denotes

However, all 3 patterns may be seen in a single lesion from the same patient.

T179

84115-84332

Epistemic_statement

denotes

The majority of inflammatory conditions of the panniculus are granulomatous or pyogranulomatous, and the histologic appearance of panniculitis caused by an infectious agent can be very similar to sterile panniculitis.

T180

84658-84718

Epistemic_statement

denotes

It can also refer to atrophy of the epidermis or the dermis.

T181

84719-84842

Epistemic_statement

denotes

Evaluation of atrophy of the epidermis and dermis should always take into account the site from which the biopsy was taken.

T182

85594-85769

Epistemic_statement

denotes

The literature on ichthyosiform disorders in human medicine is extensive and complex, and, not unlike veterinary medicine, molecular tests are not available for all disorders.

T183

87168-87260

Epistemic_statement

denotes

Neither ichthyosis vulgaris nor X-linked ichthyosis has been documented in domestic animals.

T184

87453-87620

Epistemic_statement

denotes

In humans, ARCI may manifest as 1 of 3 clinical forms: lamellar ichthyosis (LI), nonbullous congenital ichthyosiform erythroderma (CIE), and harlequin ichthyosis (HI).

T185

87621-87736

Epistemic_statement

denotes

The phenotypes of LI and CIE are often overlapping, and some patients may switch phenotypes with age and treatment.

T186

88073-88193

Epistemic_statement

denotes

Although LI is often associated with the transglutaminase 1 (TGM1) gene, it is by no means specific for a TGM1 mutation.

T187

88194-88390

Epistemic_statement

denotes

To date, 8 genes have been associated with ACRI: TGM1, ABCA12, ABHD5 (CG158), 2 lipoxygenases (ALOXE3 and ALOX12B), a NIPA-like domain containing 4 (NIPAL4 or ICTHYIN), LIPN, CYP4F22, and PNPLA-1.

T188

88391-88630

Epistemic_statement

denotes

The diagnosis of ichthyosiform disorders is based on the following: signalment, history, character and distribution of the scale, presence or absence of extracutaneous lesions, and skin biopsy analysis, perhaps including molecular testing.

T189

88631-88722

Epistemic_statement

denotes

For breeding dogs, molecular testing, if available, may be needed to identify carrier dogs.

T190

88723-88938

Epistemic_statement

denotes

A pathologist should be able to narrow the mutational causes by determining if the disorder is epidermolytic (rare but uniquely associated with keratin mutations) or nonepidermolytic (more common and less specific).

T191

89015-89113

Epistemic_statement

denotes

They may be hereditary or result from other factors that were present during development in utero.

T192

89114-89375

Epistemic_statement

denotes

Various environmental influences, such as infectious agents, nutrient imbalances, toxic chemicals and plants, and ambient temperature, present during gestation, can bring about abnormalities in the skin and hair that are present at birth but are not hereditary.

T193

89480-89581

Epistemic_statement

denotes

Congenital abnormalities of the skin may be associated with abnormalities of other tissues or organs.

T194

89582-89786

Epistemic_statement

denotes

In contrast, although they are genetically determined, some hereditary abnormalities of skin (genodermatoses) are not apparent at birth and may instead be manifested later in life, that is, tardive onset.

T195

89787-89865

Epistemic_statement

denotes

For example, color-dilution alopecia may not be evident until early adulthood.

T196

90097-90238

Epistemic_statement

denotes

New genetic disorders are being recognized at an increasing rate as the degree of diagnostic sophistication of veterinary medicine has grown.

T197

90386-90637

Epistemic_statement

denotes

Once an analogous genetic disease is identified in animals, affected animals may be used to gain new knowledge regarding the genetics, pathogenesis, or treatment of the condition, thereby producing reciprocal benefits for both human and animal health.

T198

90903-91002

Epistemic_statement

denotes

The gene is thought to play a role in lipid organization and metabolism within the outer epidermis.

T199

91076-91169

Epistemic_statement

denotes

Unlike the Golden Retriever, the Bulldogs consistently develop clinical signs before weaning.

T200

91590-91632

Epistemic_statement

denotes

Malassezia yeast overgrowth may be severe.

T201

91763-91846

Epistemic_statement

denotes

The clinical presentation may be misinterpreted as nonseasonal atopic skin disease.

T202

91847-91901

Epistemic_statement

denotes

Occasional adult dogs may have footpad hyperkeratosis.

T203

91902-92055

Epistemic_statement

denotes

The disorder has been linked to ICHTHYN, and similar to the PLPLA1 mutation in Golden Retrievers, is likely related to lipid metabolism in the epidermis.

T204

92763-92988

Epistemic_statement

denotes

A number of other breeds have been diagnosed with NI on light microscopy and clinical examination (Soft-coated Wheaten Terriers, West Highland White Terriers), but further molecular characterizations have not been documented.

T205

92989-93070

Epistemic_statement

denotes

Many cases are likely confirmed on skin biopsy and do not receive further workup.

T206

93071-93267

Epistemic_statement

denotes

A congenital and familial form of keratoconjunctivitis sicca with scaling has been documented in Cavalier King Charles Epidermolytic ichthyosis is also referred to as epidermolytic hyperkeratosis.

T207

93698-93783

Epistemic_statement

denotes

The biochemical basis is most often associated with a defect in the K1 and K10 genes.

T208

94123-94279

Epistemic_statement

denotes

To date, the nonepidermolytic forms of ichthyosis, which have been characterized in dogs, have been documented or presumed to be autosomal recessive traits.

T209

94280-94511

Epistemic_statement

denotes

Nonepidermolytic ichthyosis (NI) is not necessarily recessive (e.g., X-linked ichthyosis and autosomal dominant ichthyosis vulgaris are also nonepidermolytic); however, these disorders have yet to be documented in domestic animals.

T210

94512-94643

Epistemic_statement

denotes

Veterinary pathologists currently label these ARCI disorders by their breed predilection, a practice that may change in the future.

T211

94763-94938

Epistemic_statement

denotes

The clinical presentation consists of large, soft, white-to-gray adherent scale that is prominent on the trunk and may be associated with ventral hyperpigmentation (eFig.6-2).

T212

95185-95290

Epistemic_statement

denotes

Golden Retrievers are typically diagnosed at <1 year of age; however, adult-onset cases are not uncommon.

T213

95291-95420

Epistemic_statement

denotes

Some dogs develop secondary bacterial folliculitis, which may lead to pruritus and clinical confusion with allergic skin disease.

T214

95421-95500

Epistemic_statement

denotes

The disease may wax and wane with periodic bouts of exacerbation and remission.

T215

95501-95542

Epistemic_statement

denotes

Golden Retriever ichthyosis is caused by

T216

95543-95642

Epistemic_statement

denotes

Wattles (tassels), similar to those seen in goats, occur occasionally in swine and rarely in sheep.

T217

95868-95924

Epistemic_statement

denotes

They are 5-7 cm long and may be unilateral or bilateral.

T218

98179-98229

Epistemic_statement

denotes

A recessive mode of inheritance has been proposed.

T219

98346-98498

Epistemic_statement

denotes

An X-linked dominant mode of inheritance has been suggested in Rottweilers because the 5 reported dogs were female, and no male relatives were affected.

T220

99089-99225

Epistemic_statement

denotes

In Labradors, the condition may be confused with a presumably immune-mediated adult-onset form of mural folliculitis with parakeratosis.

T221

99489-99537

Epistemic_statement

denotes

The mode of inheritance has not been determined.

T222

99659-99776

Epistemic_statement

denotes

Ichthyosis has been reported in many breeds of cattle, and the mode of inheritance appears to be autosomal recessive.

T223

99914-100099

Epistemic_statement

denotes

However, the underlying molecular defect(s) is unknown, and it is uncertain whether the forms are distinct diseases or merely represent variations in expression of a single abnormality.

T224

100660-100746

Epistemic_statement

denotes

The skin is dry, hard, and inflexible like old leather, and may be prominently folded.

T225

101151-101380

Epistemic_statement

denotes

Histologic changes in the skin are mild to moderate perivascular dermatitis, moderate to marked acanthosis that may be accompanied by pallor of the superficial epidermis, and marked diffuse parakeratotic hyperkeratosis (see eFig.

T226

101388-101534

Epistemic_statement

denotes

There may also be neutrophilic exocytosis, intraepidermal neutrophilic pustules, and serocellular crusts containing bacterial cocci and/or yeasts.

T227

101610-101774

Epistemic_statement

denotes

If this information is not available, differential diagnoses include superficial necrolytic dermatitis, zinc-responsive dermatosis, and generic dog food dermatosis.

T228

101775-101911

Epistemic_statement

denotes

However, parakeratosis is less severe in these diseases, and superficial epidermal necrolysis is not a feature of lethal acrodermatitis.

T229

101912-102175

Epistemic_statement

denotes

Much of the older literature uses the term epitheliogenesis imperfecta (EI) to describe congenital mechanobullous conditions in many species; however, many of these conditions would be more appropriately termed epidermolysis bullosa in the current classification.

T230

102316-102460

Epistemic_statement

denotes

In swine, aplasia cutis congenita (also called epitheliogenesis imperfecta) is very rare and a clinically distinct, recessively inherited trait.

T231

102577-102662

Epistemic_statement

denotes

Piglets with small focal lesions may survive but are smaller than normal littermates.

T232

102898-102948

Epistemic_statement

denotes

Piglets may have fluid-filled subcutaneous bullae.

T233

102949-102982

Epistemic_statement

denotes

An underlying cause is not known.

T234

102983-103228

Epistemic_statement

denotes

Epidermolysis bullosa is divided into 3 broad groups based on the ultrastructural level of the skin cleavage: epidermolysis bullosa simplex (EBS; epidermolytic epidermolysis bullosa), then appear around the eyes, ears, and intermandibular space.

T235

103386-103454

Epistemic_statement

denotes

The flanks, perianal area, and ventral abdomen may also be affected.

T236

103455-103599

Epistemic_statement

denotes

The hair may lighten in color, a change that may be especially prominent around the eyes and resemble the spectacle lesion of copper deficiency.

T237

103600-103671

Epistemic_statement

denotes

Affected calves are lethargic, drool, and may have difficulty suckling.

T238

103912-104067

Epistemic_statement

denotes

This disease is associated with impaired intestinal zinc absorption caused by abnormal function of a protein belonging to a family of zinc-uptake proteins.

T239

104068-104153

Epistemic_statement

denotes

Acrodermatitis enteropathica and HZD are associated with defects in the gene SLC39A4.

T240

104154-104287

Epistemic_statement

denotes

Oral zinc supplementation effects a complete reversal of clinical signs and may restore thymic morphology if instituted early enough.

T241

104567-104720

Epistemic_statement

denotes

A cysteine-rich intestinal protein (CRIP) has been identified in the liganddependent pathway and has been suggested as being defective in this condition.

T242

105168-105241

Epistemic_statement

denotes

Neutrophilic exocytosis and superficial bacterial cocci may be prominent.

T243

105242-105434

Epistemic_statement

denotes

Lethal acrodermatitis of Bull Terrier dogs is also thought to be caused by an abnormality in zinc absorption or metabolism; however, zinc supplementation fails to produce clinical improvement.

T244

106734-106913

Epistemic_statement

denotes

Extracutaneous postmortem lesions consist of a small or absent thymus and may also include a high, arched palate and 533.e1 eFigure 6-5 Lethal acrodermatitis of Bull Terrier dogs.

T245

107466-107658

Epistemic_statement

denotes

Whereas hemidesmosomes may be normal or reduced in size and number in the non-Herlitz type, they are markedly reduced or absent with an absent sub-basal dense plate in the Herlitz type of JEB.

T246

107995-108147

Epistemic_statement

denotes

Affected animals usually develop lesions shortly after birth; however, in some cases, the disease is not evident until the animal is several months old.

T247

108148-108264

Epistemic_statement

denotes

Initial lesions consist of vesicles and bullae, but they quickly rupture, and only ulcers may be evident clinically.

T248

108571-108716

Epistemic_statement

denotes

Lesions may be induced accidentally by rough handling of an affected animal or intentionally for diagnostic purposes by gentle frictional trauma.

T249

108987-109150

Epistemic_statement

denotes

Even in the epidermolytic form of epidermolysis bullosa, the cleavage is usually so low in the epidermis that the vesicle appears subepidermal in routine sections.

T250

109151-109319

Epistemic_statement

denotes

PAS staining to visualize the basement membrane zone may be helpful in determining the level of cleavage, but definitive diagnosis requires ultrastructural examination.

T251

109320-109493

Epistemic_statement

denotes

Basement membrane antigen mapping by immunofluorescence or immunohistochemistry may be a diagnostic adjunct or alternative to electron microscopy to establish the diagnosis.

T252

110075-110275

Epistemic_statement

denotes

In calves, epidermolysis bullosa (termed EI) has been reported in many breeds and appears to be an autosomal recessive trait, and it is seen most often in herds in which there is extensive inbreeding.

T253

110494-110557

Epistemic_statement

denotes

JEB may be further classified into Herlitz or non-Herlitz type.

T254

110901-111073

Epistemic_statement

denotes

The clinical presentation may range from minimal localized involvement of hands and feet to severe, life-threatening generalized blistering with extracutaneous involvement.

T255

111270-111398

Epistemic_statement

denotes

In animals, epidermolysis bullosa has been reported rarely and, in most instances, has led to the death of affected individuals.

T256

112052-112285

Epistemic_statement

denotes

• In junctional epidermolysis bullosa, clefting occurs within the lamina lucida because of abnormalities of the anchoring filament-hemidesmosome complexes, which may be reduced in number and poorly formed or may be completely absent.

T257

113193-113351

Epistemic_statement

denotes

The PASpositive basement membrane zone remained attached to the epithelium and formed the roof of the vesicle, suggestive of dystrophic epidermolysis bullosa.

T258

113433-113609

Epistemic_statement

denotes

Ultrastructural examination of skin from the Swiss lambs indicated that the splitting was below the lamina densa and that anchoring fibrils were absent or rare and rudimentary.

T259

113610-113848

Epistemic_statement

denotes

Antigen mapping of the lesion identified laminin and type IV collagen at the roof of the cleft, which confirms sublamina densa blistering; and no type VII collagen, the major structural component of anchoring fibrils, could be identified.

T260

113849-113929

Epistemic_statement

denotes

These findings are consistent with the dystrophic form of epidermolysis bullosa.

T261

114126-114325

Epistemic_statement

denotes

The unaffected twin brother of this buck was bred over 5 consecutive years with the dam and produced 12 kids, 4 of which were affected with DEB, suggesting an autosomal recessive mode of inheritance.

T262

115115-115185

Epistemic_statement

denotes

The proximal esophagus may also be affected and hooves may be lacking.

T263

115430-115535

Epistemic_statement

denotes

Extracutaneous lesions are rare, and included ocular lesions in one foal and dental dysplasia in another.

T264

115713-115834

Epistemic_statement

denotes

Ultrastructurally, the separation is located within the lamina lucida, indicating that hemidesmosomes are underdeveloped.

T265

115900-116160

Epistemic_statement

denotes

The mutation responsible-a cytosine insertion in exon 10 of the LAMC2 gene-has also been identified in JEB phenotype horses in 2 commonly; however, any portion of the body may be affected as well as the squamous epithelium of the muzzle, lips, and oral cavity.

T266

116161-116219

Epistemic_statement

denotes

Hooves and dewclaws may be missing or incompletely formed.

T267

117404-117548

Epistemic_statement

denotes

Three animals kept under laboratory conditions showed gradual improvement in severity of lesions, but rough handling could still elicit lesions.

T268

119380-119658

Epistemic_statement

denotes

A congenital bullous disease suggestive of dystrophic epidermolysis bullosa has been described in Suffolk and South Dorset Down lambs in New Zealand, Scottish Blackface lambs, and lifelong history of trauma-induced ulcers and scars over pressure points of limbs and on footpads.

T269

120289-120343

Epistemic_statement

denotes

Epidermolysis bullosa appears to be very rare in cats.

T270

122573-122731

Epistemic_statement

denotes

A mutation in the collagen VII encoding gene COL7A1 was suggested as the cause, because this gene is mutated in all subsets of DEB in affected human patients.

T271

122793-122866

Epistemic_statement

denotes

In American Saddlebred horses, the mutation has been identified in LAMA3.

T272

122951-123124

Epistemic_statement

denotes

However, the initial cases reported as epidermolysis bullosa simplex in young Collies are now thought to represent a mild form of dermatomyositis with unrecognized myositis.

T273

123424-123500

Epistemic_statement

denotes

Non-Herlitz (nonlethal) JEB has been documented in a 4-year-old mongrel dog.

T274

123974-124083

Epistemic_statement

denotes

Junctional EB in German Shorthaired Pointers is autosomal recessive and has been proposed as an animal model.

T275

124300-124434

Epistemic_statement

denotes

The disease is associated with reduced expression of laminin 5 and is caused by a mutation in the LAMA3 gene for the laminin α3 chain.

T276

124435-124597

Epistemic_statement

denotes

Dystrophic epidermolysis bullosa (DEB), associated with mutation in the gene encoding type VII collagen (COL7A1), has been characterized in Golden Retriever dogs.

T277

125614-125721

Epistemic_statement

denotes

Further studies have shown that keratinocytes in lesional and nonlesional skin have depleted SERCA2 stores.

T278

125722-125852

Epistemic_statement

denotes

Although the precise mechanism is not known, depletion of calcium stores may delay exit from the cell cycle and enhance apoptosis.

T279

125853-125986

Epistemic_statement

denotes

Thus the clinical appearance, histologic features, and SERCA2 abnormality suggest the disease in dogs is more similar to DD than HHD.

T280

126415-126589

Epistemic_statement

denotes

The condition is associated with a PKP1 mutation and loss of plakophilin-1 in desmosomal attachments as well as an abnormal arrangement of desmoplakin and keratins 10 and 14.

T281

128068-128263

Epistemic_statement

denotes

Although the clinical presentation of these cases was typical of epidermolysis bullosa, the histologic and ultrastructural features were unlike those of the common forms of epidermolysis bullosa.

T282

128264-128504

Epistemic_statement

denotes

However, some variants of epidermolysis bullosa simplex in humans are characterized by cleft formation with acantholysis in the middle or upper epidermis, and in some instances, cells contain round clumps within their cytoplasm produced by

T283

128505-128597

Epistemic_statement

denotes

A dominantly inherited epidermal acantholytic disease has been described in English Setters.

T284

128598-128986

Epistemic_statement

denotes

The disease was initially compared to Hailey-Hailey disease (HHD) in humans, but current thought is that the disorder is more likely a form of Darier disease (DD) In humans, autosomal dominant mutations in genes that encode calcium pumps are responsible for both HHD (SPCA1: secretory calcium/magnesium ATPase isoform) and DD (SERCA2: sarcoendoplasmic reticulum calcium ATPase isoform 2).

T285

130461-130633

Epistemic_statement

denotes

The clinical appearance of the lesions was not typical HHD, but the histologic and ultrastructural features were thought to be similar to benign familial chronic pemphigus.

T286

131296-131354

Epistemic_statement

denotes

Animals may not grow well and may have a wild temperament.

T287

131729-131828

Epistemic_statement

denotes

The condition appears to be inherited as a simple autosomal recessive trait in all breeds affected.

T288

132282-132424

Epistemic_statement

denotes

Histologic changes include small, inactive hair follicles, deformed dermal papillae lacking a vascular network, and degenerative sweat glands.

T289

132425-132682

Epistemic_statement

denotes

A HAD syndrome, with hypotrichosis, almost complete lack of teeth, and complete absence of eccrine nasolabial glands, has been observed in a family of German Holsteins; similar anomalies in humans are known as X-linked anhidrotic ectodermal dysplasia (ED1).

T290

133211-133245

Epistemic_statement

denotes

Calves may become normal with age.

T291

133405-133580

Epistemic_statement

denotes

Inherited epidermal dysplasia, also called baldy calf syndrome, is a lethal disease of Holstein-Friesian calves that is likely inherited as a single autosomal recessive trait.

T292

133581-133703

Epistemic_statement

denotes

The disease causes loss of condition and skin, horn, and hoof lesions that can be confused with inherited zinc deficiency.

T293

133704-133958

Epistemic_statement

denotes

Calves appear normal at birth, but at 1-2 months of age, they begin to lose condition despite normal appetite, and develop generalized hair loss and patchy areas of scaly, wrinkled, thickened skin over the neck, shoulders, flanks, and on pressure points.

T294

134406-134507

Epistemic_statement

denotes

Congenital hypotrichosis of Hereford cattle is thought to be due to a simple autosomal dominant gene.

T295

134549-134735

Epistemic_statement

denotes

Calves have thin, pliable skin, extremely curly facial hair, and may have sparse pelage of thin soft curly, easily broken and epilated hairs, or they may be aggregation of tonofilaments.

T296

135017-135114

Epistemic_statement

denotes

It is usually sparse, short and fine, or coarse and wiry, brittle, and easily broken or epilated.

T297

135115-135229

Epistemic_statement

denotes

Histologic changes are variable, likely a reflection of the different mutations responsible for the hypotrichosis.

T298

135494-135577

Epistemic_statement

denotes

Iodine deficiency can cause goiter and hypotrichosis in piglets, lambs, and calves.

T299

135578-135741

Epistemic_statement

denotes

Adenohypophyseal hypoplasia in Guernseys and Jerseys, and maternal ingestion of Veratrum album by Japanese cattle, has been associated with hairlessness in calves.

T300

135742-135917

Epistemic_statement

denotes

In addition, alopecia of various degrees has been associated with intrauterine infection with bovine viral diarrhea virus in calves and classical swine fever virus in piglets.

T301

136636-136735

Epistemic_statement

denotes

Sebaceous glands and arrector pili muscles appear normal; sweat glands undergo cystic degeneration.

T302

137126-137237

Epistemic_statement

denotes

Although initially healthy, all affected kittens in one report died by 13 weeks of age from various infections.

T303

137238-137453

Epistemic_statement

denotes

Postmortem examination of some of the affected Birman kittens revealed thymic aplasia and lymphoid depletion of paracortical regions of lymph nodes, spleen, and Peyer's patches, suggesting an immunologic deficiency.

T304

137582-137707

Epistemic_statement

denotes

Sebaceous glands were normal, but sweat glands were hypoplastic and in decreased number, and arrector pili muscles were rare.

T305

137708-137810

Epistemic_statement

denotes

Hereditary hypotrichosis is recognized in piglets, and there may be both dominant and recessive forms.

T306

137811-137970

Epistemic_statement

denotes

The dominant form is thought to be lethal in homozygotes; it is characterized histologically by a decreased number of hair follicles, and most appear atrophic.

T307

137971-138071

Epistemic_statement

denotes

Congenital hypotrichosis is thought to be a simple autosomal recessive trait in polled Dorset sheep.

T308

138235-138317

Epistemic_statement

denotes

Congenital hypotrichosis has been described in a Percheron, but is rare in horses.

T309

138318-138360

Epistemic_statement

denotes

Congenital hypotrichosis is rare in goats.

T310

138361-138638

Epistemic_statement

denotes

Drögemüller C, et al Hypotrichosis associated with pigmentary alterations Generalized or regional alopecia attributed to follicular dysplasias that include histologic evidence of pigment abnormalities have been frequently described in dogs and less frequently in other species.

T311

138693-139058

Epistemic_statement

denotes

The first of these 2 categories is color dilution alopecia, described in color-dilute animals of breeds such as the Doberman Pinscher, Irish Setter, Dachshund, Chow Chow, Poodle, Whippet, Italian Greyhound, Boston Terrier, Chihuahua, Saluki, Yorkshire Terrier, and mongrels, in which the onset of alopecia can be tardive, generally ranging from 4 months to 3 years.

T312

139059-139139

Epistemic_statement

denotes

Puppies are born with normal hair, but develop slowly progressive alopecia (Fig.

T313

139148-139264

Epistemic_statement

denotes

Pedigree analysis in colordilute Dachshunds suggests this disorder may be inherited as an autosomal recessive trait.

T314

139562-139656

Epistemic_statement

denotes

There can be some hair follicle atrophy in chronic cases; however, this is a secondary change.

T315

140000-140091

Epistemic_statement

denotes

Arrector pili muscles are reduced in number and frequently not associated with hair shafts.

T316

140092-140223

Epistemic_statement

denotes

Ultrastructural examination indicates that the giant trichohyaline granules lack normal microfilament and macrofilament structures.

T317

140841-140933

Epistemic_statement

denotes

Affected calves also have nonregenerative anemia and fail to grow despite a normal appetite.

T318

141811-141939

Epistemic_statement

denotes

X-linked hypohidrotic ectodermal dysplasia (XHED) has been documented in dogs and the inheritance confirmed by breeding studies.

T319

142158-142243

Epistemic_statement

denotes

The lack of hair is apparent on the dorsal head, ventrum, and dorsal tail base (eFig.

T320

142406-142500

Epistemic_statement

denotes

Hairless areas may have decreased adnexal density as well as partial to complete adnexal loss.

T321

142699-142821

Epistemic_statement

denotes

This protein is thought to control some epithelialmesenchymal cell interactions that regulate development of the ectoderm.

T322

142945-143099

Epistemic_statement

denotes

A semidominant form of ectodermal dysplasia has been documented in congenitally hairless breeds (Mexican and Peruvian hairless dogs, Chinese Crested dog).

T323

143100-143292

Epistemic_statement

denotes

The disorder has been associated with a member of the forkhead box 539.e1 eFigure 6-7 Patterned hairlessness on the dorsum of the head of a dog with X-linked hypohidrotic ectodermal dysplasia.

T324

143472-143602

Epistemic_statement

denotes

Coatcolor-linked hair follicle dysplasia has also been described in buckskin Holstein cows (color-dilute tan-and-white Holsteins).

T325

144055-144248

Epistemic_statement

denotes

Black hair follicular dysplasia is thought to be an autosomal inherited disorder in mongrel puppies, and is thought to have a genetic component in some purebred animals such as Bearded Collies.

T326

144369-144472

Epistemic_statement

denotes

A difference in the appearance of the melanin clumps in whole mounts of hair shafts has been suggested.

T327

144473-144658

Epistemic_statement

denotes

In Greater Musterlanders, the hair shaft defect appears to be associated with inadequate and disorganized melanosome transfer to keratinocytes, with resultant melanin clumping (see Fig.

T328

144667-144828

Epistemic_statement

denotes

There are other follicular dysplasias associated with pigment abnormalities that do not fall easily into these 2 categories, but have similar histologic changes.

T329

144951-145053

Epistemic_statement

denotes

These are not color-dilute dogs, and the onset can be tardive, generally between 3 months and 5 years.

T330

145681-145847

Epistemic_statement

denotes

Follicular dysplasia has been described in Weimaraners, in which affected young adults had progressive alopecia of the trunk with recurrent folliculitis/furunculosis.

T331

145848-145962

Epistemic_statement

denotes

similar to color-dilution alopecia in dogs has been described in cattle as cross-related congenital hypotrichosis.

T332

145963-146116

Epistemic_statement

denotes

This has been reported in crosses involving Simmental, Gelbvieh, and Charolais cattle, most common in the Simmental-Angus and Simmental-Holstein crosses.

T333

146117-146198

Epistemic_statement

denotes

The condition appears in calves that have color-dilute (gray or chocolate) coats.

T334

146199-146282

Epistemic_statement

denotes

The affected Dermatomyositis has been identified in Shelties in the United Kingdom.

T335

146283-146429

Epistemic_statement

denotes

The disease has not been characterized as well in this breed; but it appears that myositis is a less prominent feature of the disease in Shelties.

T336

146730-147147

Epistemic_statement

denotes

The histologic changes of ischemic dermatopathy can be categorized into 5 subtypes: (1) canine familiar dermatomyositis, (2) juvenile-onset ischemic dermatopathy (similar to canine familial dermatomyositis except for the breed predispositions), (3) focal postrabies vaccination reaction, (4) generalized vaccine-induced ischemic dermatopathy, and (5) adult-onset non-vaccine-induced generalized ischemic dermatopathy.

T337

147148-147206

Epistemic_statement

denotes

The cause and pathogenesis of dermatomyositis are unknown.

T338

147207-147339

Epistemic_statement

denotes

The primary target is thought to be capillary endothelium, although histologic evidence of vessel wall inflammation is often absent.

T339

147443-147617

Epistemic_statement

denotes

Variation in expression of dermatomyositis in dogs suggests that factors other than simple autosomal dominant inheritance are involved in the etiopathogenesis of the disease.

T340

147618-147780

Epistemic_statement

denotes

Immunologic mechanisms are thought to be involved in this disease in humans, and both cell-mediated and humoral immunity have been implicated in the pathogenesis.

T341

147781-148138

Epistemic_statement

denotes

In Collies with dermatomyositis, serum levels of circulating immune complexes were found to be increased above normal before clinical disease was evident; the onset and severity of dermatitis and myositis correlated with the serum levels of circulating immune complexes and IgG, and circulating immune complex levels decreased to normal as disease resolved.

T342

148139-148240

Epistemic_statement

denotes

These findings suggest that the immune complexes initiated inflammation rather than resulted from it.

T343

148241-148378

Epistemic_statement

denotes

IgG was identified as the immunoglobulin component of the immune complexes, but the identity of the antigen component was not determined.

T344

148379-148546

Epistemic_statement

denotes

Dermatomyositis has been associated with viral, bacterial, and Toxoplasma infections, but infectious agents are generally not isolated from tissues of affected people.

T345

148547-148678

Epistemic_statement

denotes

Crystalline structures, suggestive of picornaviruses, have been seen in endothelial cells of muscle from severely affected Collies.

T346

148679-148818

Epistemic_statement

denotes

Cases in humans have also occurred following immunization, therapy with various drugs, during pregnancy, and in association with neoplasia.

T347

149242-149346

Epistemic_statement

denotes

Mucous membranes and mucocutaneous junctions may be transiently involved early in the course of disease.

T348

149347-149373

Epistemic_statement

denotes

Pawpad ulceration is rare.

T349

149469-149632

Epistemic_statement

denotes

In mildly to In cattle, follicular dysplasia has been reported in black Angus and black Angus-Brahman crosses; the histologic changes are similar to those in dogs.

T350

149633-149814

Epistemic_statement

denotes

These cattle are all black animals that are not phenotypically color dilute; however, there is adult onset of alopecia that is more commonly associated with color-dilution alopecia.

T351

149815-150188

Epistemic_statement

denotes

In view of the dysplasias in Portuguese Water dogs, black-and-red Doberman Pinschers, and black Angus and their crosses that occur in animals not phenotypically color dilute but that can have adult onset, it is quite possible that separation of follicular dysplasias with pigmentary alteration into color-dilution alopecia and black hair follicular dysplasia is artificial.

T352

150189-150412

Epistemic_statement

denotes

It is likely that these histologically similar follicular dysplasias are subtypes of a single process; however, until the mechanism underlying follicular dysplasia is characterized, the classification is somewhat arbitrary.

T353

150413-150429

Epistemic_statement

denotes

Cerundolo R, et

T354

150430-150523

Epistemic_statement

denotes

Congenital hypertrichosis, a condition characterized by an excessive amount of hair, is rare.

T355

150829-150947

Epistemic_statement

denotes

High environmental temperature during gestation has been associated with an unusual hairy appearance of newborn lambs.

T356

150948-151074

Epistemic_statement

denotes

The lambs are small, and most do not survive to weaning; the histologic appearance of this abnormality has not been described.

T357

152029-152079

Epistemic_statement

denotes

A similar disease, referred to as dermatomyositis-

T358

152080-152183

Epistemic_statement

denotes

Further reading The histologic changes in the skin are variable and may be quite subtle or nonspecific.

T359

152558-152708

Epistemic_statement

denotes

Diagnostically useful artifactual dermal-epidermal separation may be induced at the margins of the section by the shearing action of the punch biopsy.

T360

153244-153410

Epistemic_statement

denotes

The most consistently present histologic abnormalities are follicular atrophy and perifollicular inflammation that may be accompanied by perifollicular fibrosis (Fig.

T361

153984-154103

Epistemic_statement

denotes

A defect in any one of these skin molecules can result in structural and functional abnormalities of the entire tissue.

T362

154104-154280

Epistemic_statement

denotes

Inherited connective tissue disorders of skin may consist of abnormalities involving only one of these components, or there may be concurrent alterations in several components.

T363

154281-154512

Epistemic_statement

denotes

Hereditary collagen dysplasia, the most commonly recognized connective tissue disease, is a complex group of disorders of collagen that results in decreased tensile strength of the skin and may also affect other connective tissues.

T364

154513-154834

Epistemic_statement

denotes

Alterations in elastic fibers and ground substance may accompany some forms of collagen dysplasia, but there moderately affected dogs, lesions may resolve spontaneously in 6-12 months, whereas in severely affected dogs, lesions may regress but do not usually resolve completely, and disease may be lifelong and extensive.

T365

155030-155105

Epistemic_statement

denotes

Lesions may be exacerbated by estrus, parturition, or exposure to sunlight.

T366

155106-155344

Epistemic_statement

denotes

Although cases of adult-onset dermatomyositis have been reported, it is likely that at least some of these dogs had mild transient lesions that were overlooked when they were pups and subsequently developed more obvious disease as adults.

T367

155547-155668

Epistemic_statement

denotes

However, because of the dolichocephalic shape of the Collie head, mild temporal or masseter muscle atrophy may be missed.

T368

155897-156025

Epistemic_statement

denotes

Generalized symmetrical muscle atrophy, weakness, and exercise intolerance may develop in moderately and severely affected dogs.

T369

156026-156065

Epistemic_statement

denotes

Megaesophagus may develop in some dogs.

T370

156066-156168

Epistemic_statement

denotes

Various additional abnormalities may accompany skin and muscle lesions in more severely affected dogs.

T371

156238-156359

Epistemic_statement

denotes

Conjunctivitis may develop in dogs with severe periocular skin lesions or because of facial palsy and inability to blink.

T372

156507-156645

Epistemic_statement

denotes

Secondary bacterial pyoderma, septicemia, or megaesophagus with secondary aspiration pneumonia may develop in more severely affected dogs.

T373

156646-156703

Epistemic_statement

denotes

Demodicosis may also be present and complicate diagnosis.

T374

157619-157701

Epistemic_statement

denotes

Inheritance may be autosomal dominant, autosomal recessive, or X-linked recessive.

T375

157702-157869

Epistemic_statement

denotes

In animals, clinical disease has been restricted almost exclusively to skin abnormalities and has been characterized in only a few breeding colonies or herd outbreaks.

T376

157870-158008

Epistemic_statement

denotes

Most instances of collagen dysplasia occur in single animals, and the molecular defect and mode of inheritance are usually not determined.

T377

158456-158567

Epistemic_statement

denotes

Extracutaneous signs, such as joint laxity and ocular abnormalities, have been reported in animals only rarely.

T378

158568-158651

Epistemic_statement

denotes

The skin is usually soft and velvety, hyperextensible, and may hang in loose folds.

T379

159188-159323

Epistemic_statement

denotes

In general, the disease tends to be most severe in sheep, less severe in cattle, followed by dogs and cats, and least severe in horses.

T380

159477-159694

Epistemic_statement

denotes

In some cases, abnormalities are evident at the light microscopic level, but frequently none are found or the differences are subtle and difficult to determine except by comparison to a breed- and age-matched control.

T381

159695-159816

Epistemic_statement

denotes

The dermis may be normal, thinner than normal, or thicker than normal because of an increased amount of ground substance.

T382

159817-159912

Epistemic_statement

denotes

Collagen fibers may be widely separated, finer and paler than normal, and haphazardly arranged.

T383

159913-159986

Epistemic_statement

denotes

Rarely, increased numbers of elastic fibers are seen with elastic stains.

T384

160064-160154

Epistemic_statement

denotes

Abnormal collagen fibers may stain unevenly with collagen stains such as Masson trichrome.

T385

160155-160254

Epistemic_statement

denotes

Instead of the uniform blue staining of normal collagen, the abnormal collagen may have a red core.

T386

160255-160403

Epistemic_statement

denotes

This staining feature is not unique to collagen dysplasia, however, as uneven collagen staining also occurs with degenerative disorders of collagen.

T387

160558-160642

Epistemic_statement

denotes

In longitudinal sections, collagen fibrils may be loosely wound and flat or helical.

T388

160643-160756

Epistemic_statement

denotes

In crosssection, they may have several irregular thin projecting arms that give them a "hieroglyphic" appearance.

T389

160757-160879

Epistemic_statement

denotes

This appearance are also diseases in which an abnormality of the elastic fibers or ground substance appears to be primary.

T390

161683-161902

Epistemic_statement

denotes

In Border-Leicester-Southdown crossbred lambs, the biochemical abnormality was not determined, but it did not appear to be a procollagen peptidase deficiency because there was no increase in dermal procollagen detected.

T391

162102-162222

Epistemic_statement

denotes

Gross examination of the skin indicates that the dermis is moist and thicker than normal, with a jelly-like consistency.

T392

162545-162631

Epistemic_statement

denotes

No skin hyperelasticity or joint hypermobility are associated with the skin fragility.

T393

163992-164068

Epistemic_statement

denotes

Collagen dysplasia has been described in many purebred and mixed-breed dogs.

T394

164316-164501

Epistemic_statement

denotes

Ocular abnormalities and joint laxity, associated problems commonly seen in humans with Ehlers-Danlos syndrome, have been reported infrequently in dogs, and bone abnormalities are rare.

T395

164637-164879

Epistemic_statement

denotes

The biochemical abnormality has not been identified in any cases of collagen dysplasia in dogs; but the skin of Springer Spaniels with is typical of dermatosparaxis of sheep and cattle and has also been described in a Himalayan cat and a dog.

T396

165005-165166

Epistemic_statement

denotes

They may all be uniformly larger or smaller, or there is a mixed population of fibrils that extend beyond the range of normal minimum and maximum diameter sizes.

T397

165756-165900

Epistemic_statement

denotes

For unknown reasons, the same biochemical defect may produce different clinical abnormalities in different individuals and in different species.

T398

166994-167177

Epistemic_statement

denotes

Dermatosparaxis in cattle is recessively inherited as is the biochemically analogous condition in humans, Ehlers-Danlos syndrome type VII C, although clinical signs are not identical.

T399

167274-167339

Epistemic_statement

denotes

Associated joint laxity and soft bones have been reported rarely.

T400

167534-167649

Epistemic_statement

denotes

Individual collagen fibers are smaller in diameter than in normal skin, and their arrangement appears disorganized.

T401

167650-167719

Epistemic_statement

denotes

There may be an increase in dermal elastin and number of fibroblasts.

T402

169233-169276

Epistemic_statement

denotes

There may be orthokeratotic hyperkeratosis.

T403

169277-169406

Epistemic_statement

denotes

The exact pathomechanism is unknown; however, it is thought to be related to an effect of glucocorticoids on collagen production.

T404

169407-169569

Epistemic_statement

denotes

In addition, many of the associated conditions have moderate to severe liver involvement, which suggests that hepatic dysfunction may play a role in pathogenesis.

T405

170027-170132

Epistemic_statement

denotes

An abnormality of dermal proteoglycan is a rarely documented cause of fragile skin in humans and animals.

T406

170494-170624

Epistemic_statement

denotes

However, levels of dermatan collagen dysplasia has been found to have more uncross-linked α-chains than collagen from normal dogs.

T407

170625-170751

Epistemic_statement

denotes

Histologic changes may be subtle and consist of dermal thinning evident only in comparison to a section from a normal control.

T408

170752-170957

Epistemic_statement

denotes

In other cases, a decreased amount of dermal collagen, collagen disorganization, variation in collagen staining, increased number of elastic fibers, or increased amount of extracellular matrix may be seen.

T409

170958-171022

Epistemic_statement

denotes

The abnormal collagen fibers may stain red with trichrome stain.

T410

171185-171249

Epistemic_statement

denotes

A mixture of normal and abnormal collagen fibers may be present.

T411

171250-171379

Epistemic_statement

denotes

Collagen dysplasia in cats is usually referred to as cutaneous asthenia, although in early reports it was called dermatosparaxis.

T412

171380-171544

Epistemic_statement

denotes

The condition has been reported in a number of breeds; in the majority of the cases, neither the biochemical defect nor the mode of inheritance has been identified.

T413

171730-171814

Epistemic_statement

denotes

This cat could not be bred, however, and the mode of inheritance was not determined.

T414

172790-172980

Epistemic_statement

denotes

Ultrastructural examination indicates that normal and abnormal collagen fibers may be present in of weeks, the lesions continue to expand and develop a dry, horny, papilloma-like appearance.

T415

173934-173991

Epistemic_statement

denotes

Coronary band changes, however, diminish as the pig ages.

T416

173992-174115

Epistemic_statement

denotes

At birth, affected piglets seem otherwise normal, but over a period of weeks they gradually decline in growth and vitality.

T417

174588-174631

Epistemic_statement

denotes

The mode of inheritance was not determined.

T418

174918-175056

Epistemic_statement

denotes

The hyaluronan accumulation is related to a higher expression of hyaluronan synthase 2 (HAS2) mRNA and HAS2 protein by dermal fibroblasts.

T419

175271-175375

Epistemic_statement

denotes

In some dogs, large lakes of mucin form nodules or cysts that may rupture and drip clear, stringy fluid.

T420

175809-175972

Epistemic_statement

denotes

Special stains can be used to better visualize the mucin; these include Alcian blue at pH 2.5, which stains mucin blue-green, and mucicarmine, which stains it red.

T421

176497-176620

Epistemic_statement

denotes

The economic impact of the disease may be considerable because virtually all homozygotes die before reaching slaughter age.

T422

176621-176781

Epistemic_statement

denotes

Skin lesions may be present at birth, but more commonly, they develop during the first 3 weeks of life, and in rare cases may not arise until 2-3 months of age.

T423

176909-176974

Epistemic_statement

denotes

They may extend up the sides and back but do not affect the head.

T424

178168-178335

Epistemic_statement

denotes

Basal keratinocytes are the only cells in the epidermis that can undergo mitosis, and once mitosis occurs, the basal cell proceeds to undergo terminal differentiation.

T425

178645-178704

Epistemic_statement

denotes

The intercellular and cell substrate adhesions are complex.

T426

178705-178910

Epistemic_statement

denotes

Hemidesmosomes and desmosomes are stable junctions that associate with cytoplasmic keratin filaments, whereas focal adhesions and adherens junctions connect to actin filaments and are transitory adhesions.

T427

179857-179973

Epistemic_statement

denotes

The molecular structure of keratin is very important, and genetic mutation(s) can affect keratin filament formation.

T428

180657-180826

Epistemic_statement

denotes

In chronic cases, epithelialization and interstitial fibrosis are evident, and multinucleated giant cells may be infrequent when the condition has lasted several months.

T429

180827-180893

Epistemic_statement

denotes

Typical pulmonary changes may be obscured by secondary infections.

T430

181341-181489

Epistemic_statement

denotes

Although present at birth, dermoid cysts are usually asymptomatic and may not be noticed until they become distended or infected in an older animal.

T431

181490-181652

Epistemic_statement

denotes

The cyst usually contains hair, keratin, and sebum, and this material may produce progressive enlargement of the structure so that it becomes clinically apparent.

T432

181822-182086

Epistemic_statement

denotes

In dogs, dermoid cysts have been reported most commonly in the Rhodesian Ridgeback, a breed in which the lesion appears to be inherited as a simple recessive trait; development of a cyst is predisposed to by a dominant mutation in 3 fibroblast growth factor genes.

T433

182150-182233

Epistemic_statement

denotes

It is unknown whether the lesion is an inherited condition in other breeds of dogs.

T434

182234-182367

Epistemic_statement

denotes

Dermoid cysts have been associated with multiple vertebral and spinal malformations and hindlimb neurologic deficits in several dogs.

T435

182368-182578

Epistemic_statement

denotes

The rare condition of nasal dermoid sinus cyst results in a discharging sinus over the external nares in dogs; the cyst may extend into the cranial vault and cause cerebral abscessation or recurrent meningitis.

T436

182690-182774

Epistemic_statement

denotes

Dermoid cysts are rare in cats, and both cases reported were in domestic shorthairs.

T437

182775-182815

Epistemic_statement

denotes

Dermoid cysts may be single or multiple.

T438

182967-183058

Epistemic_statement

denotes

A tuft of hair may protrude through this pore, and it may be surrounded by a whorl of hair.

T439

183059-183273

Epistemic_statement

denotes

The cyst may end blindly in the subcutis; it may connect to the dorsal spinous process of vertebrae directly or by a fibrous cord; or rarely, it extends down to be continuous with the dura mater of the spinal cord.

T440

184202-184410

Epistemic_statement

denotes

In the 1980s, this designation was potentially useful for treatment purposes, but it antedated the discovery of numerous hyperkeratotic conditions, with sebaceous adenitis and ichthyosis being prime examples.

T441

184587-184801

Epistemic_statement

denotes

Primary idiopathic seborrheic skin disease is reported in many breeds and has been suggested to have an inherited basis; however, the breed predilections and clinical lesions overlap those of allergic skin disease.

T442

185032-185228

Epistemic_statement

denotes

In Cocker Spaniels, cell proliferation kinetics indicate that seborrheic individuals have increased epithelial cell proliferation of the epidermis, hair follicle infundibulum, and sebaceous gland.

T443

185229-185379

Epistemic_statement

denotes

In addition, recombinant grafting studies have shown that the hyperproliferative epidermis from seborrheic Cocker Spaniels remains hyperproliferative.

T444

186069-186236

Epistemic_statement

denotes

In Labrador Retrievers, the distribution is often strikingly ventral ("water-line disease"), which in the current literature would be interpreted as atopic dermatitis.

T445

186237-186424

Epistemic_statement

denotes

Thus many cases that would have been called "primary seborrhea" in the past would now be classified as pyoderma, Malassezia dermatitis, sebaceous adenitis, allergic dermatitis, and so on.

T446

186425-186517

Epistemic_statement

denotes

Therefore "seborrhea" should be used only as a clinical descriptive, not an etiologic, term.

T447

186989-187093

Epistemic_statement

denotes

The parakeratosis is typically found overlying the shoulders of follicular ostia (parakeratotic "caps").

T448

187260-187347

Epistemic_statement

denotes

Spongiform or Munro's microabscesses may be seen in conjunction with the parakeratosis.

T449

188773-188863

Epistemic_statement

denotes

Keratinocytes forming the SC are dead and can be sloughed when desmosomes are broken down.

T450

188864-189053

Epistemic_statement

denotes

Hydrolytic enzymes, such as cathepsin B-like, carboxypeptidase, and acid phosphatase, are thought to be responsible for this desmosomal degradation and subsequent keratinocyte desquamation.

T451

189829-189946

Epistemic_statement

denotes

Seborrhea literally means "flow of sebum," and it has been loosely correlated with abnormal sebaceous gland function.

T452

190029-190161

Epistemic_statement

denotes

Scaling (i.e., seborrhea) is a common reaction of the skin to normalize a damaged skin barrier and can occur with almost any insult.

T453

190316-190427

Epistemic_statement

denotes

Acne is usually asymptomatic, although some cats may develop secondary bacterial folliculitis and furunculosis.

T454

190428-190540

Epistemic_statement

denotes

The clinical lesions appear on the chin and lips and include comedones, papules, alopecia, crusts, and erythema.

T455

190831-190908

Epistemic_statement

denotes

Either sex may be affected, and the condition usually develops early in life.

T456

190909-191019

Epistemic_statement

denotes

The disorder may represent a form of inherited follicular dysplasia or a follicular disorder of cornification.

T457

191223-191299

Epistemic_statement

denotes

Occasionally, secondary bacterial folliculitis and furunculosis may develop.

T458

191784-191898

Epistemic_statement

denotes

The enlargement is usually firm to slightly spongy, and associated with partial alopecia, scaling, and greasiness.

T459

192026-192164

Epistemic_statement

denotes

In most instances, canine tail gland hyperplasia is associated with hormonal imbalances, especially elevated levels of blood testosterone.

T460

192305-192458

Epistemic_statement

denotes

The entire dorsal surface of the tail in cats is replete with large, densely packed sebaceous glands, which are proposed to be embryonal hepatoid glands.

T461

192754-192937

Epistemic_statement

denotes

The cause of feline tail gland hyperplasia is unknown, and the colloquialism "stud tail" is misleading, as the condition is also seen in intact females and neutered males and females.

T462

193512-193652

Epistemic_statement

denotes

The cases may have subordinate patterns of suppurative folliculitis, furunculosis, perifolliculitis, and intraepidermal pustular dermatitis.

T463

193653-193761

Epistemic_statement

denotes

Primary seborrhea oleosa, presumably of autosomal recessive inheritance, has been described in Persian cats.

T464

194253-194304

Epistemic_statement

denotes

Generalized primary seborrhea is rare in the horse.

T465

194697-194825

Epistemic_statement

denotes

The etiology and pathogenesis are unknown, and aside from an association with puberty, there is little similarity to human acne.

T466

194826-194976

Epistemic_statement

denotes

The lesions are thought to develop from external hair follicle trauma (rubbing of face) that results in follicular inflammation and traumatic rupture.

T467

194977-195100

Epistemic_statement

denotes

The lesions consist of follicular papules and pustules on the chin and lips that may ulcerate and ooze suppurative exudate.

T468

195278-195363

Epistemic_statement

denotes

Early lesions may exhibit follicular keratosis, comedones, and variable inflammation.

T469

195755-195958

Epistemic_statement

denotes

The lesions are considered benign epidermal neoplasms and are occurs in aged dogs and is not associated with inflammation, although the development of fissures may lead to secondary bacterial infections.

T470

196273-196398

Epistemic_statement

denotes

Digital hyperkeratosis can occur as a congenital and presumed hereditary disorder in the Irish Terrier and Dogue de Bordeaux.

T471

196569-196638

Epistemic_statement

denotes

An autosomal mode of inheritance has been shown in the Irish Terrier.

T472

196639-196763

Epistemic_statement

denotes

This condition arises in Labradors Retrievers and their crosses at <1 year of age, and is thought to be autosomal recessive.

T473

197634-197707

Epistemic_statement

denotes

It occurs in many breeds; however, Quarter Horses seem to be predisposed.

T474

197996-198069

Epistemic_statement

denotes

The lesions are usually asymptomatic, and may be persistent or permanent.

T475

198070-198186

Epistemic_statement

denotes

The etiology of the condition is unknown but may involve an immune-mediated attack on the wall of the hair follicle.

T476

198187-198227

Epistemic_statement

denotes

The reason for the linearity is unknown.

T477

198386-198450

Epistemic_statement

denotes

Multinucleated giant cells and eosinophils are variably present.

T478

198451-198647

Epistemic_statement

denotes

Sebaceous glands can be secondarily effaced, and there is a variable amount of orthokeratotic or parakeratotic hyperkeratosis, with or without superficial perivascular nonsuppurative inflammation.

T479

198823-198932

Epistemic_statement

denotes

It represents a localized form of seborrheic dermatosis, can occur at any age, and has no breed predilection.

T480

199420-199493

Epistemic_statement

denotes

The base of the horn must be inspected for the possible underlying cause.

T481

199868-200112

Epistemic_statement

denotes

The term nevus implies a lesion present at birth and composed of mature elements, and therefore, because these linear hyperkeratotic lesions have in common an early age of onset, they may represent linear epidermal nevi that have tardive onset.

T482

200113-200339

Epistemic_statement

denotes

Equine cannon keratosis is grossly and histologically similar to linear epidermal nevi but differs from the linear epidermal nevi of Belgian horses, as it can occur at any age, and is restricted to the skin of the cannon area.

T483

200462-200655

Epistemic_statement

denotes

The condition has been reported in more than 50 breeds of dogs and in mongrels; however, there are breed predilections for the Standard Poodle, Akita, Samoyed, Vizsla, Lhasa Apso, and Havanese.

T484

200656-200729

Epistemic_statement

denotes

In Standard Poodles and Akitas, an autosomal recessive trait is proposed.

T485

200802-200916

Epistemic_statement

denotes

There appears to be a slight sex predilection for males in Standard Poodles, Havanese dogs, and Springer Spaniels.

T486

200917-201007

Epistemic_statement

denotes

very common in humans but rarely diagnosed in middle age to older dogs (mean age 9 years).

T487

201008-201091

Epistemic_statement

denotes

They are of unknown cause, and have nothing to do with the clinical term seborrhea.

T488

201092-201185

Epistemic_statement

denotes

The lesions may be single or multiple and have no apparent breed, sex, or site predilections.

T489

201495-201682

Epistemic_statement

denotes

This proliferation of monomorphic basaloid keratinocytes undergoes abrupt cornification and surrounds impacted, hyperkeratotic follicular ostia, which may develop into keratin horn-cysts.

T490

201683-201820

Epistemic_statement

denotes

The lesions can be confused with viral plaques and are distinguished by the lack of hypergranulosis and papillomavirus cytopathic effect.

T491

201821-201935

Epistemic_statement

denotes

In humans, the sudden appearance or enlargement of multiple lesions can be associated with an internal malignancy.

T492

201936-201991

Epistemic_statement

denotes

This association has not been made in domestic animals.

T493

201992-202179

Epistemic_statement

denotes

Lichenoid keratoses have been reported as single or occasionally multiple wart-like papules or hyperkeratotic plaques that may be hyperpigmented on the inner surface of the pinna in dogs.

T494

202180-202234

Epistemic_statement

denotes

Age, breed, and sex predilections have not been noted.

T495

202501-202817

Epistemic_statement

denotes

Lichenoid reaction patterns in dogs, and rarely cats, may correspond to specific diseases (e.g., uveodermatologic syndrome, discoid lupus), but an idiopathic lichenoid reaction (lichenoid dermatosis) is occasionally seen in dogs and may represent a poorly characterized form of chronic cutaneous lupus erythematosus.

T496

202818-203036

Epistemic_statement

denotes

Idiopathic lichenoid dermatosis is characterized by usually asymptomatic, symmetrical, grouped, flattopped papules and plaques that are variably distributed, and that develop a scaly to markedly hyperkeratotic surface.

T497

203037-203130

Epistemic_statement

denotes

The lesions have been described as self-limiting, although resolution may take several years.

T498

203357-203514

Epistemic_statement

denotes

Apoptotic keratinocytes can be seen primarily, although not exclusively, in the basal layer, and there is often hydropic degeneration of basal keratinocytes.

T499

203515-203698

Epistemic_statement

denotes

If focal areas of suppurative epidermitis and/or suppurative luminal folliculitis are present, a lichenoid tissue reaction in response to staphylococcal infection should be suspected.

T500

203699-203837

Epistemic_statement

denotes

A lichenoid psoriasiform dermatosis may occur in dogs on long-standing oral cyclosporine for refractory allergic skin or other conditions.

T501

203907-204032

Epistemic_statement

denotes

Some are of unknown cause; others originate from papillomas, basal cell tumors, squamous cell carcinomas, or other keratoses.

T502

204033-204118

Epistemic_statement

denotes

In cattle, sheep, and goats, cutaneous horns may arise in lesions of dermatophilosis.

T503

204119-204366

Epistemic_statement

denotes

In the cat, multiple cutaneous horns on the footpads have been reported in association with feline leukemia virus (FeLV) infection; FeLV was isolated from the horns, and type C viral particles were seen in the lesions with the electron microscope.

T504

204367-204470

Epistemic_statement

denotes

Cutaneous horns may be single or multiple, and have no apparent age, breed, sex, or site predilections.

T505

204549-204662

Epistemic_statement

denotes

They may be small (1-mm diameter × 5-mm length) or quite large 551.e1 eFigure 6-10 Seborrheic keratosis in a dog.

T506

204884-204950

Epistemic_statement

denotes

The pathogenesis of this disease has not been fully characterized.

T507

205362-205557

Epistemic_statement

denotes

In the predisposed breeds, such as Standard Poodles and Akita, a genetic basis seems probable together with other factors that would explain the variation in onset and progression of the disease.

T508

205576-205594

Epistemic_statement

denotes

Histopathological

T509

205595-205732

Epistemic_statement

denotes

This disorders occurs almost exclusively in adult Cocker Spaniels, but has been reported in a Labrador Retriever and Miniature Schnauzer.

T510

205733-205783

Epistemic_statement

denotes

True vitamin A deficiency has not been documented.

T511

205927-205986

Epistemic_statement

denotes

The dogs may have a greasy haircoat with ceruminous otitis.

T512

207050-207172

Epistemic_statement

denotes

In short-coated dogs, early lesions consist of patches of scaling and alopecia that tend to appear on the ears and dorsum.

T513

207649-207749

Epistemic_statement

denotes

Inflammation can occasionally impinge secondarily on the follicular epithelium causing folliculitis.

T514

207750-207850

Epistemic_statement

denotes

Orthokeratotic and/or parakeratotic hyperkeratosis together with follicular keratosis can be marked.

T515

207851-207982

Epistemic_statement

denotes

In the chronic stages, both active inflammation and sebaceous glands may be absent, and there may be perifollicular fibrosis ( Fig.

T516

208702-208877

Epistemic_statement

denotes

The base of the hyperplastic epithelium can have a scalloped appearance with crowding of basilar keratinocytes, and there is multifocal spongiosis with lymphocytic exocytosis.

T517

209101-209254

Epistemic_statement

denotes

The absence of Malassezia organisms in histologic sections does not necessarily exclude their presence as the organisms may be lost in tissue processing.

T518

209515-209526

Epistemic_statement

denotes

Congenital

T519

209527-209610

Epistemic_statement

denotes

Equine coronary band dystrophy is a condition of unknown etiology and pathogenesis.

T520

209880-209977

Epistemic_statement

denotes

Usually all 4 limbs are affected; however, the lesion may not encompass the entire coronary band.

T521

210041-210094

Epistemic_statement

denotes

Cracks and fissures may develop and lead to lameness.

T522

210095-210164

Epistemic_statement

denotes

The chestnuts and ergots are similarly affected and may be ulcerated.

T523

210321-210454

Epistemic_statement

denotes

There may be various degrees of neutrophilic and eosinophilic intraepidermal microabscesses (containing eosinophils and neutrophils).

T524

210455-210558

Epistemic_statement

denotes

Although the infiltrate may obscure the dermoepidermal junction, basal cell apoptosis is not a feature.

T525

210729-210827

Epistemic_statement

denotes

Lichenoid psoriasiform dermatosis can also occur in any dog on long-standing cyclosporine therapy.

T526

210893-210974

Epistemic_statement

denotes

An association with staphylococcal infection has been proposed for the condition.

T527

211079-211177

Epistemic_statement

denotes

It occurs primarily in the Dachshund, although it can be seen in other breeds with pendulous ears.

T528

211393-211550

Epistemic_statement

denotes

The dermatosis may be complicated by secondary bacterial infection and fissures, at which point ulceration, oozing, crusting, pain, and pruritus may be seen.

T529

211736-211749

Epistemic_statement

denotes

Gross TL, et

T530

211750-211836

Epistemic_statement

denotes

This refers to a cutaneous reaction pattern that can be associated with many diseases.

T531

211837-211930

Epistemic_statement

denotes

Clinically, it is characterized by scaling and erythema that can be localized or generalized.

T532

211931-212106

Epistemic_statement

denotes

Most cases of exfoliative dermatosis have been reported in association with thymoma, epitheliotropic lymphoma, visceral malignant neoplasms, drug reactions, or are idiopathic.

T533

212107-212350

Epistemic_statement

denotes

Histopathologic findings can reflect the underlying condition and can include parakeratosis, epidermal acanthosis, variable psoriasiform epidermal hyperplasia, variable lymphocytic exocytosis, and perivascular to lichenoid dermal inflammation.

T534

212726-212845

Epistemic_statement

denotes

It is usually postinflammatory, a result of minor or chronic irritation, and may be accompanied by mild hyperkeratosis.

T535

213133-213282

Epistemic_statement

denotes

It is usually associated with an accelerated melanocyte turnover with an increased number of melanosomes, as occurs following trauma and UV exposure.

T536

213283-213362

Epistemic_statement

denotes

Inflammatory mediators likely play a role in stimulating melanocyte production.

T537

213363-213471

Epistemic_statement

denotes

Activation of pre-existing immature melanocytes by sunlight, estrogen, and progesterone is thought to occur.

T538

213472-213599

Epistemic_statement

denotes

Endothelin-1, which is produced and secreted by keratinocytes after UV irradiation, has been shown to accelerate melanogenesis.

T539

213600-213691

Epistemic_statement

denotes

Basic fibroblast growth factor (bFGF) has been shown to be a mitogen for human melanocytes.

T540

213692-213875

Epistemic_statement

denotes

Proliferating human epidermal cells in culture produce bFGF, perhaps illustrating the mechanism behind the hyperplastic and hyperpigmented lesions that typify many chronic dermatoses.

T541

213876-213941

Epistemic_statement

denotes

Acquired hyperpigmentation may also involve hair (melanotrichia).

T542

213942-214132

Epistemic_statement

denotes

This is usually seen as a result of inflammatory skin disorders, especially those caused by biting insects in the horse and also has been described in white Merino sheep exposed to UV light.

T543

214410-214495

Epistemic_statement

denotes

Lesions tend to start at <1 year of age and may increase in size and number with age.

T544

214875-214943

Epistemic_statement

denotes

Low numbers of melanophages may be present in the underlying dermis.

T545

215069-215141

Epistemic_statement

denotes

Merino sheep may acquire pigmented macules, particularly after shearing.

T546

215142-215220

Epistemic_statement

denotes

Lesions are concentrated on the back, suggesting a role for sunlight exposure.

T547

215901-215920

Epistemic_statement

denotes

Menzies-Gow NJ, et

T548

215921-216014

Epistemic_statement

denotes

The ichthyoses are rare disorders of cornification that result in severe generalized scaling.

T549

216541-216628

Epistemic_statement

denotes

Genetic mutations affecting any of these steps can lead to hereditary hypopigmentation.

T550

216629-216752

Epistemic_statement

denotes

Many such mutations have been characterized in the murine model, but this area has been little studied in domestic animals.

T551

216753-216997

Epistemic_statement

denotes

Many types of exogenous influences, such as inflammation, ultraviolet (UV) radiation, endocrinopathies, autoimmune diseases, and nutritional status can affect melanocytes in the skin, resulting in acquired hypopigmentation or hyperpigmentation.

T552

216998-217223

Epistemic_statement

denotes

Melanin synthesis in melanocytes takes place in melanosomes, which are round or elliptical membrane-bound organelles thought to be derived from endoplasmic reticulum and containing enzymes from the Golgi and lysosomal system.

T553

218167-218438

Epistemic_statement

denotes

Apart from tyrosinase, the molecular role of these gene products has not been completely characterized, but it appears that platelet-derived growth factor (PDGF), and receptors for fibroblast growth factor-2 (FGF-2), endothelin-B, and the Steel factor (cKIT) are crucial.

T554

218439-218542

Epistemic_statement

denotes

Cutaneous pigmentary disorders can be divided into disorders of hyperpigmentation and hypopigmentation.

T555

218544-218764

Epistemic_statement

denotes

Hereditary hypopigmentation can be divided into melanocytopenic hypomelanosis, characterized by the absence of melanocytes in affected areas, and melanopenic hypomelanosis, in which melanocytes are present but defective.

T556

218765-218831

Epistemic_statement

denotes

The condition can be localized, focally extensive, or generalized.

T557

218832-218947

Epistemic_statement

denotes

Melanocytopenic hypomelanosis can be extensive, as is seen in animals with Waardenburg syndromes and in piebaldism.

T558

219080-219217

Epistemic_statement

denotes

Melanocytopenic hypomelanosis can also be localized, as in vitiligo, in which there is genetically programmed destruction of melanocytes.

T559

219520-219682

Epistemic_statement

denotes

In cats, this has been shown to be due to an autosomal dominant mutation with complete penetrance for loss of pigmentation and incomplete penetrance for deafness.

T560

220513-220686

Epistemic_statement

denotes

The defect has been shown to be a mutation in the gene encoding c-kit tyrosine kinase receptor, or a mutation in the gene for stem cell factor, which is the receptor ligand.

T561

220687-220784

Epistemic_statement

denotes

The c-kit tyrosine kinase receptor is associated with proliferation and survival of melanoblasts.

T562

221011-221168

Epistemic_statement

denotes

Vitiligo has been described in the dog, cat, horse, cattle, and the Smyth chicken (DAM chicken), which has been used as an animal model of the human disease.

T563

221334-221529

Epistemic_statement

denotes

It is thought to be a polygenic disease necessitating simultaneous mutations in several genes, resulting in melanocyte destruction or increased risk of immune-mediated destruction of melanocytes.

T564

221530-221892

Epistemic_statement

denotes

Theories regarding the pathogenesis of this disease include autoimmune destruction of melanocytes, a neurogenic theory involving release of a neurochemical from peripheral nerves that inhibits melanogenesis, a self-destruction theory that involves failure of protection of melanocytes against the toxic effects of melanin precursors, or a combination of factors.

T565

221893-222018

Epistemic_statement

denotes

Circulating antimelanocytic antibodies have been detected in some studies, lending support to an immunemediated pathogenesis.

T566

222712-222787

Epistemic_statement

denotes

Spongiosis, neutrophilic exocytosis, and serous crusts may also be present.

T567

222989-223175

Epistemic_statement

denotes

In view of the early age of onset (usually <1 year of age) and the strong predilection for Dachshunds, it is probable that canine idiopathic acanthosis nigricans is a heritable disorder.

T568

223176-223438

Epistemic_statement

denotes

In humans, some forms of acanthosis nigricans are associated with internal malignancies, hyperinsulinemia, insulin resistance, drug administration, endocrine dysfunction, and concurrent autoimmune disease; a similar correlation has not been demonstrated in dogs.

T569

223439-223803

Epistemic_statement

denotes

The histologic lesions of primary acanthosis nigricans are virtually identical to the common histologic changes associated with chronic pruritic dermatitides (sometimes referred to as pseudoacanthosis nigricans or secondary acanthosis nigricans) resulting from several causes, including chronic pyoderma, atopy, seborrheic dermatitis, and some endocrine disorders.

T570

224085-224318

Epistemic_statement

denotes

It is a condition in which coat color can be influenced by external temperature (high temperatures producing light hairs, low temperatures producing dark hairs) and factors affecting heat production and loss (alopecia, inflammation).

T571

224633-224685

Epistemic_statement

denotes

Leukoderma and leukotrichia may occur independently.

T572

224686-224842

Epistemic_statement

denotes

They can result from a decrease in melanin (hypomelanosis), a complete absence of melanin (amelanosis), or from a loss of existing melanin (depigmentation).

T573

225885-225939

Epistemic_statement

denotes

The skin remains white but can develop pigmented nevi.

T574

226351-226484

Epistemic_statement

denotes

This results in a membrane defect leading to the formation of giant melanosomes that are passed with difficulty to the keratinocytes.

T575

228011-228037

Epistemic_statement

denotes

The etiology is not known.

T576

228304-228383

Epistemic_statement

denotes

The disease can start at any age, but is more common in horses <2 years of age.

T577

228581-228615

Epistemic_statement

denotes

Siamese cats may develop vitiligo.

T578

229162-229252

Epistemic_statement

denotes

Coat color dilution and black hair follicular dysplasia has been reported in many species.

T579

229462-229561

Epistemic_statement

denotes

In cats, dilute coat color is thought to be due to an autosomal recessive trait (Maltese dilution).

T580

229935-230056

Epistemic_statement

denotes

In general, the severity of the injury determines whether an insult will result in hypopigmentation or hyperpigmentation.

T581

230057-230255

Epistemic_statement

denotes

Mild injury results in pigmentary incontinence and epidermal hypopigmentation; however, a mild injury allows accelerated keratinocyte turnover and a subsequent increase in production of melanosomes.

T582

230497-230633

Epistemic_statement

denotes

Depigmenting lesions in horses may result from contact with equipment, such as rubber bit guards or crupper straps or with feed buckets.

T583

230758-230923

Epistemic_statement

denotes

In dogs, hypopigmentation can occur in immune-mediated diseases, such as lupus erythematosus, drug eruptions, bullous pemphigoid, and the various forms of pemphigus.

T584

231066-231137

Epistemic_statement

denotes

Microbial lesions, such as deep pyoderma, may heal with depigmentation.

T585

231437-231549

Epistemic_statement

denotes

Subcutaneous injection of corticosteroid or progesterone hormones may lead to focal hypopigmentation in the dog.

T586

231550-231711

Epistemic_statement

denotes

Canine uveodermatologic syndrome (Vogt-Koyanagi-Harada-like syndrome) is a depigmenting condition that partially resembles an extremely rare condition in humans.

T587

232763-232846

Epistemic_statement

denotes

Welldocumented precise descriptions of the expected histologic lesions are lacking.

T588

232847-233048

Epistemic_statement

denotes

Some reports indicate an interface lichenoid dermatitis may be present, whereas others suggest that a mild superficial dermal mononuclear cell infiltrate and pigmentary incontinence are to be expected.

T589

233049-233091

Epistemic_statement

denotes

The etiology and pathogenesis are unknown.

T590

233298-233340

Epistemic_statement

denotes

The etiology and pathogenesis are unknown.

T591

233573-233814

Epistemic_statement

denotes

Leukotrichia, also termed poliosis, has been reported in dogs in association with Vogt-Koyanagi-Harada-like syndrome, tyrosinase deficiency in Chow Chows, and as an idiopathic, possibly heritable condition in a litter of Labrador Retrievers.

T592

233860-233912

Epistemic_statement

denotes

Leukotrichia can be associated with alopecia areata.

T593

234158-234270

Epistemic_statement

denotes

Copper deficiency may be simple or conditioned by other dietary substances, particularly sulfate and molybdenum.

T594

234475-234636

Epistemic_statement

denotes

Hip dysplasia in dogs can lead to elbow hygromas, as dogs develop an abnormal method of lying down that relies upon dropping to the olecranons to spare the hips.

T595

234914-235013

Epistemic_statement

denotes

The wall of the hygroma is dense connective tissue that may have a smooth or a villus inner lining.

T596

235179-235260

Epistemic_statement

denotes

A flattened layer of fibroblasts may give the appearance of an epithelial lining.

T597

235261-235301

Epistemic_statement

denotes

The cavity may contain clumps of fibrin.

T598

235596-235735

Epistemic_statement

denotes

Studies in Greyhounds suggest that intermittent repeated focal vascular occlusion leads to increased tissue damage from reperfusion injury.

T599

235736-235860

Epistemic_statement

denotes

Thromboxane A 2 and its metabolite, thromboxane B 2, are thought to contribute to vasoconstriction and platelet aggregation.

T600

236494-236586

Epistemic_statement

denotes

In grade III, the ulcer extends into the deep fascia, and the wound edges may be undermined.

T601

236587-236701

Epistemic_statement

denotes

Grade IV ulcers extend to bone, have undermined edges, and possibly underlying osteomyelitis and septic arthritis.

T602

237347-237439

Epistemic_statement

denotes

Histologically, the epidermis is hyperplastic, spongiotic, and possibly eroded or ulcerated.

T603

237440-237526

Epistemic_statement

denotes

Surface pustules, neutrophilic exocytosis, and pigmentary incontinence may be present.

T604

237671-237809

Epistemic_statement

denotes

Traumatic injury to the skin is quite common in dogs and is often associated with compound fractures sustained in motor vehicle accidents.

T605

237810-237900

Epistemic_statement

denotes

Post-traumatic alopecia may occur on the lower back in cats with history of pelvic injury.

T606

238025-238159

Epistemic_statement

denotes

A plethora of foreign bodies may penetrate the canine integument, 2 of the more dramatic examples being foxtails and porcupine quills.

T607

238441-238579

Epistemic_statement

denotes

Chemical toxins may exert their effect directly as in irritant contact dermatitis or envenomation or indirectly, as in thallium poisoning.

T608

239277-239455

Epistemic_statement

denotes

Callosities can develop in all domestic animal species, but are most common in dogs, particularly the giant breeds, and in pigs housed on concrete floors with inadequate bedding.

T609

239562-239687

Epistemic_statement

denotes

Dilated hair follicles may lead to furunculosis with severe suppurative to pyogranulomatous dermatitis and eventual fibrosis.

T610

239790-239811

Epistemic_statement

denotes

Ulceration may occur.

T611

239812-239846

Epistemic_statement

denotes

The pig may also develop bursitis.

T612

239938-240232

Epistemic_statement

denotes

Hygromas are most common in the giant breeds of dogs at pressure points such as the lateral aspect of the elbow, the greater trochanter of the femur, and of anaplastic characteristics in the lymphoid cells may differentiate these lesions, sometimes termed pseudolymphoma, from genuine lymphoma.

T613

240233-240437

Epistemic_statement

denotes

Vaccine administration in cats has been linked to the development of a variety of sarcomas, including fibrosarcomas, osteosarcomas, malignant fibrous histiocytomas, chondrosarcomas, and rhabdomyosarcomas.

T614

240739-240844

Epistemic_statement

denotes

Antigen load and degree of inflammation present at the vaccination site are possible influencing factors.

T615

240845-241037

Epistemic_statement

denotes

Aluminum adjuvant particles have been identified in tumor-associated macrophages; however, vaccineassociated sarcomas have also been documented to arise from the use of nonadjuvanted vaccines.

T616

241038-241264

Epistemic_statement

denotes

Injection of killed rabies vaccine in dogs can lead to focal mononuclear vasculitis and ischemic atrophy of surrounding follicles, resulting in a focal area of alopecia and is further discussed under Immunemediated dermatoses.

T617

241768-241901

Epistemic_statement

denotes

Tail tip necrosis of feedlot beef cattle is a disease in which slatted floor housing has been shown to be an important causal factor.

T618

243302-243412

Epistemic_statement

denotes

Cutaneous wounds are common in horses and can be attributed largely to the flighty temperament of the species.

T619

243757-243899

Epistemic_statement

denotes

Retrievers or other animals wounded with steel shot may develop fistulous tracts or abscesses as steel shot corrodes when embedded in tissues.

T620

243900-244083

Epistemic_statement

denotes

Myospherulosis is a rare form of foreign-body reaction in which endogenous erythrocytes interact with an exogenous substance, such as antibiotics or ointments, or with endogenous fat.

T621

244235-244355

Epistemic_statement

denotes

These structures may resemble fungal organisms but are negative with fungal special stains such as periodic acid-Schiff.

T622

244683-244782

Epistemic_statement

denotes

The lesions are focal patches of cutaneous atrophy and alopecia that may become eroded and crusted.

T623

244837-244930

Epistemic_statement

denotes

The epidermis is thin and may occasionally show single-cell necrosis, erosion, or ulceration.

T624

244931-245011

Epistemic_statement

denotes

The hair follicles are inactive and atrophic, pale staining, and appear "faded."

T625

245086-245242

Epistemic_statement

denotes

Pyotraumatic dermatitis or "hot spot" is a common complication of flea-bite hypersensitivity or any pruritic dermatosis that leads to an itch-scratch cycle.

T626

245895-245947

Epistemic_statement

denotes

The surface may be colonized by gram-positive cocci.

T627

246153-246246

Epistemic_statement

denotes

The predominantly neutrophilic reaction tends to be restricted to the area beneath the ulcer.

T628

246247-246448

Epistemic_statement

denotes

Folliculitis and furunculosis are not features of classic pyotraumatic dermatitis but occasionally are concurrent conditions as indicated clinically by scattered papules at the periphery of the lesion.

T629

246585-246663

Epistemic_statement

denotes

Subcutaneously administered vaccines and therapeutic drugs may be responsible.

T630

246664-246742

Epistemic_statement

denotes

The nodules may ulcerate or fistulate and are often suspected to be neoplasms.

T631

246910-246941

Epistemic_statement

denotes

Lymphocytes may form follicles.

T632

247318-247446

Epistemic_statement

denotes

The heterogeneity of the cell population and the lack and perifollicular hemorrhage may reflect the trauma applied to the hairs.

T633

247447-247595

Epistemic_statement

denotes

Skin biopsies are helpful to identify an allergic reaction pattern in suspected cases; however, a normal biopsy cannot confirm psychogenic alopecia.

T634

247870-248064

Epistemic_statement

denotes

As pruritus in the cat is manifested in part by excessive grooming, any degree of perivascular eosinophilic dermatitis should be considered indicative of an underlying hypersensitivity disorder.

T635

248482-248557

Epistemic_statement

denotes

A biopsy should show evidence of the underlying hypersensitivity condition.

T636

248668-248762

Epistemic_statement

denotes

The gross lesions may be slight, but the superficial excoriations often develop into pyoderma.

T637

248947-248998

Epistemic_statement

denotes

Allergic skin disease may be a predisposing factor.

T638

249353-249394

Epistemic_statement

denotes

Secondary bacterial infection may result.

T639

249741-249997

Epistemic_statement

denotes

Superficial dermal fibrosis is usually marked, and collagen fibers in dermal papillae are often arranged perpendicular to the surface Decreased blood flow has been shown in horses with experimentally induced limb wounds as compared with wounds on the body.

T640

250096-250250

Epistemic_statement

denotes

These findings further support a role for decreased perfusion as well as metabolic disturbances in the development of equine exuberant granulation tissue.

T641

250251-250424

Epistemic_statement

denotes

The gross lesion, a tumor-like mass of red-brown tissue, must be distinguished from equine sarcoid, cutaneous habronemiasis, mycoses, pythiosis, and squamous cell carcinoma.

T642

250593-250771

Epistemic_statement

denotes

A superficial layer of granulation tissue may form in association with any of the above-mentioned conditions, and the entire lesion should be examined before a diagnosis is made.

T643

251220-251300

Epistemic_statement

denotes

Although this condition does occur, it is very rare and generally overdiagnosed.

T644

251697-251787

Epistemic_statement

denotes

The condition can occur in any cat, but is most common in indoor cats and oriental breeds.

T645

252469-252808

Epistemic_statement

denotes

Microscopic examination of skin in the alopecic form is usually normal, although wrinkling of the outer root sheath and intrafollicular deposition are complex and involve such factors as the lower pH of injured tissue, mitochondrial concentration of calcium and phosphorus, and the influx of calcium into injured cells in dystrophic forms.

T646

252986-253227

Epistemic_statement

denotes

Mineralization can be localized, as in inflammatory foci (granulomas), in degenerative lesions (follicular cysts), or in neoplasms (pilomatricomas), or may be generalized as in the tissue mineralization associated with chronic renal failure.

T647

253228-253376

Epistemic_statement

denotes

Dystrophic mineralization has been associated with hyperadrenocorticism, diabetes mellitus, local inflammation, and tissue degeneration or necrosis.

T648

253377-253489

Epistemic_statement

denotes

It has also been reported in association with drug injections and severe systemic disease such as leptospirosis.

T649

253683-253713

Epistemic_statement

denotes

Metastatic calcinosis is rare.

T650

253714-253956

Epistemic_statement

denotes

It has been associated with chronic renal failure; congenital renal dysfunction, including renal dysplasia; primary hyperparathyroidism; and hypervitaminosis D. It has also been reported in dogs with systemic blastomycosis and paecilomycosis.

T651

254130-254330

Epistemic_statement

denotes

Dogs had severe granulomatous cutaneous lesions that may have been predisposed to dystrophic mineralization, but mineralizing lesions were more extensive or separate from primary inflammatory lesions.

T652

256012-256101

Epistemic_statement

denotes

Concurrent hyperphosphatemia was thought to predispose to precipitation of calcium salts.

T653

256102-256296

Epistemic_statement

denotes

Calcinosis universalis refers to widespread areas of calcinosis cutis and can be seen with hypercortisolism, percutaneous absorption of calcium-containing products, or from the epithelium ( Fig.

T654

256305-256388

Epistemic_statement

denotes

This "vertical streaking" of collagen is thought to result from chronic irritation.

T655

256524-256580

Epistemic_statement

denotes

Sebaceous glands and hair follicles appear hyperplastic.

T656

256581-256740

Epistemic_statement

denotes

In horses, the equine self-mutilation syndrome can be misinterpreted as a possible cutaneous disorder as horses bite, kick, or rub the flank or pectoral areas.

T657

256848-256894

Epistemic_statement

denotes

The condition is thought to be stress related.

T658

256895-256982

Epistemic_statement

denotes

There are no primary cutaneous lesions; however, secondary excoriations may be present.

T659

257172-257291

Epistemic_statement

denotes

The condition is associated with udder edema and increased levels of histamine in the udder tissue leading to pruritus.

T660

257293-257625

Epistemic_statement

denotes

Deposition of insoluble calcium salts within cutaneous tissues can occur as a result of injury or degeneration of skin components (dystrophic mineralization or calcification), secondary to calcium/phosphorus metabolic alterations (metastatic mineralization or calcification), as an idiopathic condition, or may occur iatrogenically.

T661

257720-257850

Epistemic_statement

denotes

Some forms of calcinosis cutis can be indistinguishable histologically from calcinosis cutis associated with hyperadrenocorticism.

T662

257851-257994

Epistemic_statement

denotes

The clinical presentation, concurrent abnormalities, signalment, and history should allow distinction of the various forms of calcinosis cutis.

T663

258142-258243

Epistemic_statement

denotes

Lesions may occur anywhere, but common sites are over the dorsal cervical region, groin, and axillae.

T664

258244-258326

Epistemic_statement

denotes

Metastatic mineralization may occur more commonly in the pawpads of cats and dogs.

T665

258882-258995

Epistemic_statement

denotes

Lesions in dogs are most often solitary but can be multiple and occur most often in large breeds <2 years of age.

T666

259388-259508

Epistemic_statement

denotes

In horses, young male Standardbred horses appear to be predisposed, and lesions are most common over the lateral stifle.

T667

259575-259690

Epistemic_statement

denotes

Initially, the lesion may be bulging, fluctuant or cystic, variably ulcerated, and contains chalky white material .

T668

259947-260073

Epistemic_statement

denotes

Over time, the lesions become firm, progressively more mineralized, and associated with dense fibrous connective tissue bands.

T669

260074-260180

Epistemic_statement

denotes

Inflammation may subside to some degree over time, and osseous or cartilaginous metaplasia may take place.

T670

260181-260282

Epistemic_statement

denotes

Epidermal sequestration or transepidermal elimination of mineralized material may lead to ulceration.

T671

260283-260390

Epistemic_statement

denotes

The pathogenesis of calcinosis circumscripta is not known; it is likely that multiple factors are involved.

T672

260391-260532

Epistemic_statement

denotes

Dystrophic mineralization secondary to previous tissue trauma has been proposed based on the predilection for skin covering bony prominences.

T673

260533-260707

Epistemic_statement

denotes

This explanation is not entirely satisfactory as the lesions do not recur after surgical excision, and trauma to these sites in large dogs would be expected to be repetitive.

T674

260708-260893

Epistemic_statement

denotes

The name "apocrine cystic calcinosis" was previously applied to calcinosis circumscripta because it has been documented to arise from degenerating, cystic apocrine (epitrichial) glands.

T675

260894-260960

Epistemic_statement

denotes

A relationship to epitrichial glands is not evident in most cases.

T676

260961-261095

Epistemic_statement

denotes

Lesions have also developed at sites of previous injections, or in association with surgical sites sutured with polydioxanone sutures.

T677

261096-261317

Epistemic_statement

denotes

Cases of calcinosis circumscripta have also been reported to occur in the pawpads of dogs and cats with chronic renal failure, and in the pawpads of an otherwise healthy German Shepherd dog and in another German Shepherd

T678

261318-261462

Epistemic_statement

denotes

Heat may be applied to the skin in a variety of forms and, depending on duration and intensity, will produce mild to severe necrotizing lesions.

T679

261562-261626

Epistemic_statement

denotes

The lowest temperature at which skin can burn is 44° C (111° F).

T680

261726-262033

Epistemic_statement

denotes

Thermal injury in domestic animals may be caused by hot liquids, steam, heating pads, hair dryers, drying cages, hot metals such as wood stoves or car engines, fires, friction from rope "scalds," electrical burns from chewing electrical wires, improperly grounded electrocautery units, or lightning strikes.

T681

262034-262118

Epistemic_statement

denotes

Linear burns may occur on the dorsum of dogs exposed to hot water from garden hoses.

T682

262219-262324

Epistemic_statement

denotes

Animals struck by lightning may show a jagged line of singed hair running down a shoulder or flank ( Fig.

T683

262408-262452

Epistemic_statement

denotes

Rarely, small animals incur microwave burns.

T684

262690-262807

Epistemic_statement

denotes

The epithelial cells show no morphologic sign of injury, although there may be surface desquamation after a few days.

T685

263035-263162

Epistemic_statement

denotes

6 -45) can occur in the absence of substantial dermal injury and often "wicks" down to involve the follicular epithelium ( Fig.

T686

263415-263493

Epistemic_statement

denotes

Healing can be complete if secondary infection does not lead to deeper injury.

T687

264578-264674

Epistemic_statement

denotes

Well-acclimatized longhaired animals can tolerate temperatures of −50° C for indefinite periods.

T688

265078-265176

Epistemic_statement

denotes

In severe cases, the ischemic necrosis results in dry gangrene and sloughing of the affected part.

T689

265373-265514

Epistemic_statement

denotes

Histologically, thermally induced tissue damage is not sharply demarcated and should dissipate gradually with increasing depth of the biopsy.

T690

265691-265880

Epistemic_statement

denotes

Lesions from thermal injury sometimes have an abnormal anatomic distribution or pattern, such as drips, angles, lines, or areas of contact that may be helpful in the differential diagnosis.

T691

266284-266387

Epistemic_statement

denotes

Pain perception may not occur until the damage is done and lesions may not be evident for up to 6 days.

T692

267106-267145

Epistemic_statement

denotes

Subcutaneous vasculitis may be present.

T693

267553-267636

Epistemic_statement

denotes

The degree of injury may not be evident for several days after the insult occurred.

T694

267698-267794

Epistemic_statement

denotes

Once lesions fully develop, the progress of injury should cease, which is helpful in making the

T695

267795-267806

Epistemic_statement

denotes

infiltrate.

T696

268276-268366

Epistemic_statement

denotes

The epidermis is thin, friable, and in some areas hyperplastic, and may become neoplastic.

T697

268414-268488

Epistemic_statement

denotes

Chronic exudative ulcers may develop but granulation tissue does not form.

T698

268489-268592

Epistemic_statement

denotes

The dermis is fibrotic with atypical fibroblasts, telangiectasia, and possibly deep arteriolar changes.

T699

269112-269308

Epistemic_statement

denotes

An abnormal skin barrier from either physical damage to the stratum corneum (e.g., excessive moisture) or pre-existing inflammatory skin disease may enhance penetration of the offending substance.

T700

269422-269556

Epistemic_statement

denotes

Strong acids or alkalis induce immediate and severe tissue damage, whereas mild detergents or soaps may require repeated applications.

T701

269814-269859

Epistemic_statement

denotes

Feces and urine are also potential irritants.

T702

270064-270141

Epistemic_statement

denotes

It may occur in any species, but is most frequent in the horse, cow, and dog.

T703

270418-270525

Epistemic_statement

denotes

An irritant reaction can occur in the ear canals of dogs being treated with topical medications for otitis.

T704

270526-270701

Epistemic_statement

denotes

The concave pinna and vertical canal may develop Full-thickness cutaneous burns have been reported to occur in black-haired spots of Dalmatians as a result of solar radiation.

T705

270912-271024

Epistemic_statement

denotes

The absorption of visible light (400-700 nm) can result in the production of thermal energy resulting in a burn.

T706

271211-271385

Epistemic_statement

denotes

Pain, prompting moving to the shade, was likely not perceived by the dogs as the burns were multifocal, involving only black-haired areas, and Dalmatians are primarily white.

T707

271934-272071

Epistemic_statement

denotes

In the acute form, lesions resemble actinic dermatosis with epidermal thinning, basal cell vacuolation, and possible epidermal dysplasia.

T708

272188-272290

Epistemic_statement

denotes

There may be eosinophilic, wavy elastin fibrils in the superficial dermis ("red spaghetti of Walder").

T709

272424-272588

Epistemic_statement

denotes

Karyomegaly of basal cells, dermal edema and mucinosis, hyperplastic sebaceous glands, dilated epitrichial glands, and mixed perivascular dermatitis may be present.

T710

272589-272717

Epistemic_statement

denotes

Advances in the treatment of cancer in companion animals have made the possibility of radiation-induced skin injury more likely.

T711

272718-272881

Epistemic_statement

denotes

Clinicians and pathologists need to be able to recognize these lesions to provide the best management options and accurate prognosis for resolution of the lesions.

T712

272882-273006

Epistemic_statement

denotes

The varieties of radiation modalities available have variable degrees of tissue penetration and potential for tissue injury.

T713

273195-273319

Epistemic_statement

denotes

The type of radiation therapy, source, dose, intensity, and duration of exposure dictate the range of possible side effects.

T714

273403-273522

Epistemic_statement

denotes

Some cells are not lethally damaged but sustain DNA damage to the extent that replication/replacement are not possible.

T715

273523-273599

Epistemic_statement

denotes

The effects of radiation damage can be divided into acute and chronic forms.

T716

273684-273760

Epistemic_statement

denotes

Damage is self-limiting and recovery is associated with rapid cell turnover.

T717

274450-274534

Epistemic_statement

denotes

The lesion can mimic ichthyosis, particularly if the reaction occurs in a young dog.

T718

275205-275350

Epistemic_statement

denotes

It was hypothesized that the lesions represent a severe form of contact irritant dermatitis to tiamulin or one of its metabolites in the excreta.

T719

275786-275901

Epistemic_statement

denotes

In dogs, lesions often occur on the glabrous skin of the abdomen and appear erythematous with shiny adherent scale.

T720

275902-276063

Epistemic_statement

denotes

Hyperpigmentation occurs in most species of domestic animals, but in horses, leukoderma or leukotrichia may be a permanent result of irritant contact dermatitis.

T721

276064-276113

Epistemic_statement

denotes

Severe lesions can be considered a chemical burn.

T722

276184-276347

Epistemic_statement

denotes

The histologic lesions of irritant contact can be complicated by self-trauma and can be difficult to differentiate from those of allergic contact dermatitis ( Fig.

T723

277271-277368

Epistemic_statement

denotes

Bites inflicted in the head or neck region may lead to swelling that interferes with respiration.

T724

277369-277485

Epistemic_statement

denotes

Bites of pit vipers also introduce potentially dangerous bacteria, such as Clostridia spp., into the puncture wound.

T725

278188-278365

Epistemic_statement

denotes

Thallium remains available from chemical supply companies; it has a restricted use as a rodenticide in Europe, and can be used without restrictions in some developing countries.

T726

278479-278625

Epistemic_statement

denotes

A recent case of thallium toxicosis in a dog was associated with ingestion of mycoplasma agar plates in which thallium is used as a growth medium.

T727

278746-278876

Epistemic_statement

denotes

Accidental or malicious thallium poisoning is rare and is due to the use of undestroyed supplies of old, but newly exposed, baits.

T728

279035-279062

Epistemic_statement

denotes

Absorption occurs Kimura T

T729

279063-279191

Epistemic_statement

denotes

The venom of insects, spiders, other arthropods and snakes can cause mild or severe skin lesions with or without systemic signs.

T730

279192-279506

Epistemic_statement

denotes

Effects are dependent upon composition of the venom, individual victim response, anatomic location of the envenomation, and specific characteristics of the offending organism that may be influenced by season of the year, geographic location, time since the last inflicted bite or sting, depth of injury, and so on.

T731

279992-280118

Epistemic_statement

denotes

Lesions in dogs have been documented and consist of initial swelling progressing to erythematous nodules within 10-20 minutes.

T732

280254-280316

Epistemic_statement

denotes

Necrosis includes the adnexa and may extend into the subcutis.

T733

280342-280410

Epistemic_statement

denotes

Severe type I hypersensitivity (anaphylaxis) reactions are possible.

T734

280411-280667

Epistemic_statement

denotes

Stings from hymenopteran insects, such as bees, wasps, and hornets, produce effects of a local (angioedema) or possibly systemic type I hypersensitivity reaction caused by the histamine, serotonin, and kinins in the venom (see Hypersensitivity dermatoses).

T735

280668-280736

Epistemic_statement

denotes

Multiple-sting dermatoses lead to toxic reactions that can be fatal.

T736

280737-280917

Epistemic_statement

denotes

Spider bites are rarely documented definitively in animal or human patients as the initial bite goes unnoticed, and the spider is no longer recoverable by the time lesions develop.

T737

281254-281396

Epistemic_statement

denotes

The brown recluse spider (Loxosceles reclusus) is the spider most well known to induce dermal necrosis, although there are a number of others.

T738

281692-281720

Epistemic_statement

denotes

Ulceration may be extensive.

T739

281821-281919

Epistemic_statement

denotes

The epidermis and dermis undergo necrosis that may extend into the subcutis and underlying muscle.

T740

281920-281948

Epistemic_statement

denotes

Panniculitis may be present.

T741

282064-282136

Epistemic_statement

denotes

Brown recluse spider bites in humans can also lead to massive hemolysis.

T742

282272-282330

Epistemic_statement

denotes

There may be focal necrosis of sweat and sebaceous glands.

T743

282649-282799

Epistemic_statement

denotes

Secondary bacterial bronchopneumonia may occur as a result of the damage to ciliated epithelia and resultant disturbance of the mucociliary apparatus.

T744

282861-282990

Epistemic_statement

denotes

Focal suppurative pancreatitis has been described in several animals, but its causal relationship to thallium is not established.

T745

284353-284403

Epistemic_statement

denotes

The mechanism of toxicity is not fully understood.

T746

284404-284432

Epistemic_statement

denotes

There are 2 main hypotheses.

T747

284634-284852

Epistemic_statement

denotes

The second, which is based on the similarity of ionic radii between thallium and potassium, suggests that thallium may replace potassium in many critical biochemical functions, thus acting as a general cellular poison.

T748

284853-284963

Epistemic_statement

denotes

The toxic effect may be, in part, the result of thallium interacting adversely with derivatives of riboflavin.

T749

284964-285056

Epistemic_statement

denotes

Thallium can depolarize nerve cell membranes and antagonize effects of calcium on the heart.

T750

285366-285405

Epistemic_statement

denotes

Death by respiratory failure may occur.

T751

285406-285519

Epistemic_statement

denotes

Animals may survive the acute episode to develop the chronic syndrome or may bypass the acute disease altogether.

T752

285943-286020

Epistemic_statement

denotes

The mucous membranes are characteristically "brick-red" and may be ulcerated.

T753

286345-286473

Epistemic_statement

denotes

In more chronic cases, thick scales on the footpads resemble "hard pad" disease conventionally associated with canine distemper.

T754

286474-286586

Epistemic_statement

denotes

In less severely affected animals, ease of depilation may be the only clinical indication of thallium poisoning.

T755

286587-286644

Epistemic_statement

denotes

The pathogenesis of the alopecia is not fully understood.

T756

286645-286810

Epistemic_statement

denotes

Although thallium enters the hair, as do other heavy metals, by binding to sulfhydryl groups in the keratin, this is unlikely to be destructive to the hair follicle.

T757

286811-286918

Epistemic_statement

denotes

Thallium may interfere with the energy metabolism of the rapidly dividing matrix cells of anagen follicles.

T758

287149-287219

Epistemic_statement

denotes

However, no club attachment is formed, and the hairs are rapidly shed.

T759

287790-287865

Epistemic_statement

denotes

Partial or fullthickness necrosis of the surface epithelium may also occur.

T760

288456-288562

Epistemic_statement

denotes

In experimental toxicosis of calves, the cutaneous lesions were limited to scaly patches without alopecia.

T761

288673-288746

Epistemic_statement

denotes

Selenium is a metalloid that acts as an antioxidant with toxic potential.

T762

288879-289002

Epistemic_statement

denotes

Experimental studies in rodents suggest that selenium may diminish UV radiation-induced skin damage when applied topically.

T763

289003-289068

Epistemic_statement

denotes

However, some forms are strong contact irritants and vesiculants.

T764

289069-289232

Epistemic_statement

denotes

The toxic potential of selenium in the diet varies by the chemical form present, nature of the diet, rate of consumption, and by the species and individual animal.

T765

289233-289406

Epistemic_statement

denotes

The mechanism by which selenium might exert its effects on the integument is not known, but conceivably, being competitive with sulfur, it modifies the structure of keratin.

T766

290132-290289

Epistemic_statement

denotes

Seleniferous plants can selectively concentrate selenium in their foliage and seeds as compared with nonseleniferous species grown under the same conditions.

T767

290440-290564

Epistemic_statement

denotes

The former, which include members of the genus Astragalus, Machaeranthera, and Stanleya, may accumulate >1,000 ppm selenium.

T768

291351-291432

Epistemic_statement

denotes

Safe standards for levels of arsenic in drinking water have not been established.

T769

291659-291935

Epistemic_statement

denotes

Chronic arsenic exposure in humans occurs in environmental (water contamination) and industrial settings and is associated with increased incidence of visceral and cutaneous malignancies, Bowen's disease, palmar and solar hyperkeratoses, and cutaneous pigmentary disturbances.

T770

292066-292177

Epistemic_statement

denotes

Arsenic may lead to cellular proliferation through increased production of keratinocyte-derived growth factors.

T771

292941-293023

Epistemic_statement

denotes

Lesions may affect oral cavity, lips, other mucocutaneous junctions, and the feet.

T772

293024-293238

Epistemic_statement

denotes

Less is known about the effects of chronic systemic exposure of arsenic on the skin in animals; however, chronic arsenic poisoning in farm animals is associated with ill thrift and a dry, seborrheic, alopecic coat.

T773

293240-293368

Epistemic_statement

denotes

Organomercurial toxicosis in domestic animals is associated chiefly with neurologic and renal disorders and is discussed in Vol.

T774

293429-293615

Epistemic_statement

denotes

In chronic poisoning in cattle, skin manifestations, including pustules, ulcers, hyperkeratosis, and alopecia at the tail head are described, but their pathogenesis is poorly understood.

T775

294583-294721

Epistemic_statement

denotes

High levels of selenium in the blood (>2 ppm) or integumentary tissues, such as hair, hoofwall, or sole (>10 ppm), should also be present.

T776

294722-294866

Epistemic_statement

denotes

Individual animals have a variable response to selenium exposure, and some animals with high levels of selenium may not show signs of toxicosis.

T777

295845-295905

Epistemic_statement

denotes

These chemicals have not been used in lubricants since 1953.

T778

296970-297214

Epistemic_statement

denotes

Selenium poisoning can occur whenever seleniferous plants are eaten, irrespective of levels of selenium in the soil, and it can occur whenever the levels of water-soluble selenium in the soil are high, irrespective of the botanical composition.

T779

297458-297595

Epistemic_statement

denotes

Clinically, there are acute and chronic syndromes associated with the ingestion of seleniferous plants, such as Astragalus and Oxytropis.

T780

297794-297940

Epistemic_statement

denotes

Blind staggers, characterized by neurologic signs, is probably not due to selenium alone but to other toxic principles in the seleniferous plants.

T781

297941-298092

Epistemic_statement

denotes

The second syndrome is named alkali disease because it was originally believed that the pH of the selenium-rich soils was a factor in its pathogenesis.

T782

298202-298430

Epistemic_statement

denotes

The presence of internal lesions, such as nephrosis, myocardial degeneration, and hepatic fibrosis, in chronically poisoned livestock is not found in experimentally reproduced disease, suggesting that other factors are involved.

T783

298566-298619

Epistemic_statement

denotes

Foals delivered from affected mares may have lesions.

T784

298787-298924

Epistemic_statement

denotes

Sheep do not show cutaneous lesions, although, in Australia, fleece shedding has been attributed to selenium toxicity on some properties.

T785

299037-299264

Epistemic_statement

denotes

In all species, lesions commencing at the coronary band may lead to separation and shedding of the hoof or to the formation of dystrophic grooves, cracks, or corrugations that parallel the coronary band, resulting in lameness .

T786

299659-299809

Epistemic_statement

denotes

Poisoning can be acute or chronic and is characterized by alopecia, poor growth, oral ulcerations, and goiter not prevented by iodine supplementation.

T787

300137-300249

Epistemic_statement

denotes

In vitro antemortem assays for detection of DHPdegrading bacteria can be performed on feces or ruminal contents.

T788

300250-300358

Epistemic_statement

denotes

A group of bacteria, Synergistes jonesii, can be inoculated into the rumen of livestock to prevent toxicity.

T789

300359-300472

Epistemic_statement

denotes

Mimosine has been shown to reduce DNA synthesis and to block the progression of the cell cycle by chelating iron.

T790

300656-300760

Epistemic_statement

denotes

Horses appear to be most susceptible and lose their hair, especially the long hair of the mane and tail.

T791

300871-300959

Epistemic_statement

denotes

Disturbed growth at the coronet and periople may produce dystrophic rings on the hooves.

T792

300960-301069

Epistemic_statement

denotes

There is loss of condition and weakness that perhaps is attributable to malnutrition rather than to mimosine.

T793

301370-301581

Epistemic_statement

denotes

These conditions can be considered together because the cutaneous lesions of chronic ergotism caused by Claviceps purpurea and those of poisoning by tall fescue, Festuca arundinacea or F. eliator, are identical.

T794

302598-302625

Epistemic_statement

denotes

Horn growth may be delayed.

T795

302626-302701

Epistemic_statement

denotes

The animal may die before the skin lesions are severe, if exposure is high.

T796

302702-302828

Epistemic_statement

denotes

Concurrent severe secondary infections with bovine papular stomatitis virus, papilloma virus, or dermatophytes may be present.

T797

303104-303222

Epistemic_statement

denotes

Bulls may have epididymal enlargement early in the disease process, from hyperplasia and squamous metaplasia of ducts.

T798

305176-305318

Epistemic_statement

denotes

The contaminants in the PCP compounds are thought to bind to aromatic hydrocarbon receptors in the cell nucleus and influence gene expression.

T799

305319-305368

Epistemic_statement

denotes

The response may be proliferative or suppressive.

T800

305369-305517

Epistemic_statement

denotes

Elevated levels of the compounds can be demonstrated in the liver and adipose tissue years after exposure, whereas serum levels are cleared quickly.

T801

305723-305859

Epistemic_statement

denotes

Fescue foot tends to occur with the onset of colder weather, indicating that low ambient temperatures may contribute to its development.

T802

306292-306394

Epistemic_statement

denotes

Cattle have decreased skin temperature and openmouth breathing, suggesting defective thermoregulation.

T803

306590-306872

Epistemic_statement

denotes

Ingestion of endophyte-infected fescue in horses does not lead to the visibly evident effects of peripheral vasoconstriction as in cattle, but experimental studies have demonstrated that peripheral vasoconstriction does occur, suggesting exposure could lead to foot or leg problems.

T804

306873-307029

Epistemic_statement

denotes

The more commonly recognized manifestations of fescue toxicosis in the horse are prolonged gestation, agalactia, thickened placentas, and possible abortion.

T805

307598-307634

Epistemic_statement

denotes

Marked edema of the face may follow.

T806

307881-307971

Epistemic_statement

denotes

In many instances, these lesions may represent secondary mycotic or bacterial involvement.

T807

308300-308445

Epistemic_statement

denotes

The pathogenesis of the lesion is thought to be contact irritant dermatitis due directly to the T-2 toxin or to a urinary metabolite, HT-2 toxin.

T808

308645-308752

Epistemic_statement

denotes

Various other trichothecene mycotoxins are also cutaneous irritants and may cause vomition or feed refusal.

T809

309082-309173

Epistemic_statement

denotes

It may occur in animals at pasture but is more common in housed animals fed infected grain.

T810

309517-309580

Epistemic_statement

denotes

6-50 ), but ischemic necrosis may extend to the mid-metatarsus.

T811

309704-309735

Epistemic_statement

denotes

The necrotic tissue may slough.

T812

309887-310077

Epistemic_statement

denotes

The toxicosis can be produced experimentally in sheep, but the syndrome is quite different from that in cattle, being characterized by ulceration of the tongue and of the alimentary mucosae.

T813

310078-310191

Epistemic_statement

denotes

Sows are relatively resistant but may develop agalactia as a result of central inhibition of prolactin secretion.

T814

311877-311996

Epistemic_statement

denotes

Sarcoidosis in man has a genetic basis and is thought to represent a hypersensitivity response to a persistent antigen.

T815

312155-312224

Epistemic_statement

denotes

The cause of the granulomatous diseases listed above remains unclear.

T816

312225-312329

Epistemic_statement

denotes

Nor is it certain whether they represent one entity or a common tissue reaction to a variety of insults.

T817

312565-312775

Epistemic_statement

denotes

Factors that support this hypothesis are the resemblance of the histologic lesions to a type IV hypersensitivity response, age incidence, low morbidity, genetic influence, and possible need for repeat exposure.

T818

312776-312933

Epistemic_statement

denotes

Lymphocyte blastogenesis and cutaneous hypersensitivity studies have not substantiated this hypothesis; however, only a few vetch antigens have been studied.

T819

313160-313441

Epistemic_statement

denotes

Quassinoid compounds, such as neoquassin and quassin found in hardwood trees of the genus Quassia (Simarouba amara) in the family Simaroubaceae, have been reported to be associated with a vesiculobullous dermatitis of the skin around the eyes, nose, ears, anus, and lips of horses.

T820

315591-315678

Epistemic_statement

denotes

The kidney may have radially oriented cortical infiltrates that follow the vasculature.

T821

315679-315791

Epistemic_statement

denotes

Other affected organs may include the mammary and salivary glands, liver, urinary bladder, meninges, and spleen.

T822

316959-317059

Epistemic_statement

denotes

The episode in Wales was associated with the introduction of a new silage additive on several farms.

T823

317060-317171

Epistemic_statement

denotes

The outbreak in the Netherlands was associated with the feeding of di-ureido-isobutane (DUIB) in the seed cake.

T824

317997-318119

Epistemic_statement

denotes

Nucleoprotein is susceptible to UV radiation damage, resulting in mitotic inhibition and, if extensive enough, cell death.

T825

318120-318253

Epistemic_statement

denotes

Sublethal damage may promote mutagenesis or carcinogenesis by the formation of thymidine dimers between pyrimidine base pairs of DNA.

T826

318254-318447

Epistemic_statement

denotes

Pyrimidine dimer repair mechanisms normally correct DNA damage prior to cell replication; however, repeated or extensive damage may lead to failure of repair mechanisms and cell transformation.

T827

318448-318540

Epistemic_statement

denotes

The "sunburn cell" associated with UV damage is a keratinocyte that has undergone apoptosis.

T828

318541-318743

Epistemic_statement

denotes

UVB-induced keratinocyte apoptosis is a complex event that involves cytokines such as tumor necrosis factor-α and probable p53-mediated induction of apoptosis in cells sustaining substantial DNA damage.

T829

318744-318967

Epistemic_statement

denotes

Studies in mice have shown that UVB radiation-induced apoptotic keratinocytes are replaced by hyperproliferative keratinocytes, leading to epidermal hyperplasia, suggesting that apoptosis and hyperplasia are related events.

T830

319199-319290

Epistemic_statement

denotes

These findings indicate that UV radiation can serve as both a tumor initiator and promoter.

T831

319291-319479

Epistemic_statement

denotes

UV radiation may also alter immunologic reactivity in favor of the growth of the tumor, through the induction of suppressor T cells and possible impairment of natural killer-cell function.

T832

319882-319937

Epistemic_statement

denotes

These may be induced within 30 minutes of sun exposure.

T833

320497-320645

Epistemic_statement

denotes

The delayed erythema reaction may be due to direct damage to endothelial cells or the release of cytokines from the radiation-damaged keratinocytes.

T834

320646-320735

Epistemic_statement

denotes

UV radiation has been shown to increase the production of keratinocyte-derived cytokines.

T835

321064-321242

Epistemic_statement

denotes

Quassinoids have been shown experimentally to have insecticidal and anthelmintic properties, whereas their derivatives have antitumor, antiulcer, and cytotoxic activity in vitro.

T836

321243-321292

Epistemic_statement

denotes

The mechanisms leading to toxicity are not known.

T837

321531-321628

Epistemic_statement

denotes

The radiant energy of the sun includes components that are potentially harmful to mammalian skin.

T838

322199-322263

Epistemic_statement

denotes

Photoallergies have not been documented conclusively in animals.

T839

322366-322556

Epistemic_statement

denotes

The terms "actinic" and "solar" are used interchangeably; however, "actinic" is defined as ultraviolet (UV) rays from sunlight and UV lamps, whereas "solar" refers to radiation from the sun.

T840

322851-322935

Epistemic_statement

denotes

Longer wavelengths of 320-400 nm constitute UVA and may augment UVB-mediated damage.

T841

323244-323435

Epistemic_statement

denotes

The greatest potential for solarinduced skin damage occurs at high altitudes and temperate latitudes during mid-summer days, and in thin, lightly pigmented, sparsely haired, sun-exposed skin.

T842

323436-323661

Epistemic_statement

denotes

An increasing prevalence of sun-induced dermatoses and tumors has been noted in humans, coincident with the depletion of the ozone layer and a consequent increase in the intensity of UV radiation reaching the earth's surface.

T843

323662-323708

Epistemic_statement

denotes

This trend may also become evident in animals.

T844

323709-324010

Epistemic_statement

denotes

Potentially, all animals are susceptible to the acute and chronic effects of actinic radiation, but the protection afforded by the haircoat, and, to a lesser extent, stratum It is important to note that UV light-induced neoplasms may arise in skin devoid of other changes suggestive of actinic damage.

T845

324011-324104

Epistemic_statement

denotes

Actinic comedones may also be present without lesions suggestive of actinic epidermal damage.

T846

324296-324424

Epistemic_statement

denotes

Restriction of lesions to nonpigmented, sparsely haired skin and a history of sun exposure should be helpful in differentiation.

T847

324425-324579

Epistemic_statement

denotes

Increased cyclooxygenase-2 (COX-2) expression appears to play an early role in actinic keratosis and squamous cell carcinoma in rodent studies and humans.

T848

324955-325089

Epistemic_statement

denotes

Basal keratinocytes with melanin granules forming protective caps over the nucleus have an increased distribution in sun-exposed skin.

T849

325090-325272

Epistemic_statement

denotes

In chronically sun-damaged skin, pigment distribution can become irregular because of impaired transfer of melanin from melanocytes to keratinocytes, thereby weakening host defenses.

T850

325610-325721

Epistemic_statement

denotes

The lesions in cats typically affect the tips of the ears, nose, eyelids, and lips of white, blue-eyed animals.

T851

325798-325824

Epistemic_statement

denotes

The ear tip may curl over.

T852

326021-326118

Epistemic_statement

denotes

Although any age group may be affected, the condition is most severe in suckling and weaner pigs.

T853

326119-326167

Epistemic_statement

denotes

Occasionally, severely affected ears may slough.

T854

326643-326726

Epistemic_statement

denotes

Such lesions are probably related to the basking behavior exhibited by the animals.

T855

326840-326871

Epistemic_statement

denotes

Hemorrhagic bullae may develop.

T856

327042-327219

Epistemic_statement

denotes

This change may be present prior to clinical signs of actinic dermatitis and may be used as an indicator of solar damage if the history, anatomic site, and breed are supportive.

T857

327887-328036

Epistemic_statement

denotes

Oxygen free radicals may also be formed indirectly, as the result of calcium-dependent, protease-mediated activation of xanthine-oxidase in the skin.

T858

328258-328440

Epistemic_statement

denotes

The photodynamic agent usually reaches the skin via the systemic circulation, although percutaneous absorption of some photodynamic agents can cause local contact photosensitization.

T859

328441-328594

Epistemic_statement

denotes

The agent may originate externally, or it may be an endogenous substance that has accumulated to an abnormal degree as a result of metabolic dysfunction.

T860

330327-330431

Epistemic_statement

denotes

The ventral surface of the tongue is frequently affected in cattle if constantly exposed during licking.

T861

330432-330612

Epistemic_statement

denotes

In sheep, the susceptible sites are the ears, eyelids, face, muzzle, and coronets, although the back may be affected in animals with an open fleece or that have been shorn closely.

T862

330666-330777

Epistemic_statement

denotes

In horses, lesions are most common on the face, perineum, and distal extremities but may affect any white skin.

T863

330872-330953

Epistemic_statement

denotes

Photosensitization is rare in dogs and cats, and causative agents remain obscure.

T864

331035-331137

Epistemic_statement

denotes

COX-2 expression has been shown in feline, canine, and equine cutaneous squamous cell carcinoma (SCC).

T865

331138-331264

Epistemic_statement

denotes

Furthermore, use of COX-2 inhibitors may have a therapeutic role in the prevention or management of actinic keratosis and SCC.

T866

331265-331494

Epistemic_statement

denotes

Solar elastosis, a hallmark of chronic sun exposure in humans, has been described only rarely in dogs, cats, sheep, and horses and essentially represents disorganization of dermal components caused by altered fibroblast function.

T867

331598-331731

Epistemic_statement

denotes

Solar elastosis appears in H&Estained sections as scattered or agglomerated, thick, irregular, basophilic degenerate elastic fibers .

T868

331732-331828

Epistemic_statement

denotes

Silver impregnation staining techniques may be needed to demonstrate elastin changes in animals.

T869

332545-332594

Epistemic_statement

denotes

Solar keratoses may also develop cutaneous horns.

T870

332595-332716

Epistemic_statement

denotes

Differential diagnosis should include other vesicular or necrotizing dermatopathies, including chemical or thermal burns.

T871

332847-332987

Epistemic_statement

denotes

Lesions limited to areas of contact, such as the extremities, ventrum, or muzzle, suggests the presence of a contact photosensitizing agent.

T872

332988-333106

Epistemic_statement

denotes

Multiple affected animals in a herd suggest exposure to a photosensitizing agent rather than a photoallergic reaction.

T873

333107-333359

Epistemic_statement

denotes

Types I, II, and III photosensitivities can be differentiated by signalment and concurrent clinical signs, such as evidence of liver disease combined with examination of pastures and feedstuffs, and investigating photodynamic drug or chemical exposure.

T874

333360-333560

Epistemic_statement

denotes

The Candida albicans inhibition assay is a simple, inexpensive, quantitative, and relatively rapid assay for screening plants and feedstuffs for potential primary contact or systemic photosensitizers.

T875

333603-333690

Epistemic_statement

denotes

Thin-layer chromatography techniques may be useful in identifying phototoxic compounds.

T876

333691-333875

Epistemic_statement

denotes

Analysis of suspect vegetation for the identification and quantification of fungal spores may be needed to establish fungal organisms and associated mycotoxins as contributing factors.

T877

334563-334720

Epistemic_statement

denotes

Hypericin is present at all stages of plant growth but significant amounts are consumed by livestock only when the plant is prolific or other feed is scarce.

T878

334721-334834

Epistemic_statement

denotes

Other related plants that can lead to hypericism include goatweed, Tipton weed, amber, cammock, and Klamath weed.

T879

335757-335841

Epistemic_statement

denotes

These have been associated with phytophotocontact dermatitis in pigs in New Zealand.

T880

336166-336276

Epistemic_statement

denotes

The very marked edema of the ears in sheep causes them to droop, and swelling of the muzzle may cause dyspnea.

T881

336551-336582

Epistemic_statement

denotes

Vesicles or bullae may develop.

T882

336707-336862

Epistemic_statement

denotes

Necrosis is frequently seen on the upper surfaces of the ears of sheep; the tips typically curl upward as a result of mummification or may slough entirely.

T883

337113-337244

Epistemic_statement

denotes

Icterus typically is associated with hepatogenous photosensitization, but hepatogenous photosensitization may occur in its absence.

T884

337245-337422

Epistemic_statement

denotes

Economic losses in livestock can be severe due to damaged hides, weight loss, fly strikes, secondary infections, and reluctance of animals to let the young nurse damaged udders.

T885

337423-337481

Epistemic_statement

denotes

In severe episodes of photosensitization, animals may die.

T886

337607-337684

Epistemic_statement

denotes

Injury to erythrocytes in cutaneous circulation may produce severe hemolysis.

T887

337685-337851

Epistemic_statement

denotes

Histologic lesions mirror the gross lesions with coagulative necrosis of the epidermis and possibly the follicular epithelium, adnexal glands, and superficial dermis.

T888

338030-338099

Epistemic_statement

denotes

Fibrinoid degeneration of vessel walls and thrombosis may be present.

T889

338262-338411

Epistemic_statement

denotes

The disease is known as "osteohemochromatosis" and "pink tooth," both suggested by the red-brown coloration of porphyrin pigments in dentin and bone.

T890

338412-338607

Epistemic_statement

denotes

The pigment is also deposited in other tissues, but the discoloration may be obvious only in lungs, spleen, and kidney, in which it is deposited in the interstitial tissue and tubular epithelium.

T891

339134-339299

Epistemic_statement

denotes

Reactive oxygen species directly induced by the porphyrins or, possibly, via activation of xanthine oxidase in the skin are responsible for the cell membrane damage.

T892

340551-340596

Epistemic_statement

denotes

The defect in porcine porphyria is not known.

T893

340769-340890

Epistemic_statement

denotes

The defect is presumably a deficiency of uroporphyrinogen cosynthetase III, as has been established in humans and cattle.

T894

341487-341587

Epistemic_statement

denotes

Mild renal tubular damage caused by some toxins may further inhibit the excretion of phylloerythrin.

T895

341875-341929

Epistemic_statement

denotes

High lamb mortality may be incurred from mismothering.

T896

342039-342146

Epistemic_statement

denotes

Giant hogweed contains psoralens and has been documented to cause photodermatitis in man, ducks, and goats.

T897

342258-342341

Epistemic_statement

denotes

In addition to skin lesions, keratitis occurs frequently and may lead to blindness.

T898

342610-342769

Epistemic_statement

denotes

A second syndrome, referred to as alsike clover poisoning, is characterized by hepatic dysfunction and photodermatitis and has only been reported in the horse.

T899

342770-342897

Epistemic_statement

denotes

The toxic mechanism is not known but is thought to be due to a toxin within the plant itself or to the presence of a mycotoxin.

T900

343185-343333

Epistemic_statement

denotes

Lesions were limited to the nonpigmented, sun-exposed skin of the tricolored hounds and resolved within a short period of time with supportive care.

T901

343387-343479

Epistemic_statement

denotes

Although an ingested compound was suspected as the cause, no phototoxin could be identified.

T902

344092-344244

Epistemic_statement

denotes

Pigs develop cutaneous lesions more frequently than sheep or cattle, probably because the activating radiation is more able to penetrate the integument.

T903

345493-345605

Epistemic_statement

denotes

An immune-mediated vasculitis, in which immune complexes may be acting as photodynamic agents has been proposed.

T904

345606-345674

Epistemic_statement

denotes

Percutaneous absorption of initiating agents has not been ruled out.

T905

345771-346023

Epistemic_statement

denotes

In addition, lesions may be restricted to one white extremity, other white areas on the horse are unaffected, and the lesions do not always regress with cessation of exposure to sunlight, all indicating the lesions are not a form of photosensitization.

T906

346024-346145

Epistemic_statement

denotes

The lesions often affect the heels and must be differentiated from the other manifestations of the "greasy heel" complex.

T907

346146-346328

Epistemic_statement

denotes

The acute lesions are well demarcated, erythematous, oozing, and crusted in lesional white skin; erosion and ulceration may occur, and the affected limb may be edematous and painful.

T908

346697-346730

Epistemic_statement

denotes

Thrombi may be seen occasionally.

T909

346731-346818

Epistemic_statement

denotes

The epidermis may be eroded or ulcerated but undergoes papillary hyperplasia over time.

T910

347433-347677

Epistemic_statement

denotes

In most metabolic disturbances and deficiencies of essential nutrients, whether from dietary lack, malabsorption, the action of antimetabolites, or the body's inability to properly absorb or use nutrients, changes will be reflected in the skin.

T911

347678-347752

Epistemic_statement

denotes

The molecular basis for these skin lesions is, however, poorly understood.

T912

347870-348025

Epistemic_statement

denotes

A larger number can be occurs provided the animal is on a chlorophyll-rich diet and is exposed to sufficient solar radiation of the appropriate wavelength.

T913

348377-348468

Epistemic_statement

denotes

The cause of hepatic damage may be a plant toxin, mycotoxin, infectious agent, or chemical.

T914

348998-349162

Epistemic_statement

denotes

Cases of kleingrass induced-photosensitization are sporadic, potentially related to environmental conditions and have been reported in Australia, Africa, and Texas.

T915

349163-349300

Epistemic_statement

denotes

Some plants work in combination; black sagebrush appears to precondition sheep to photosensitization caused ultimately by Tetradymia spp.

T916

349671-349733

Epistemic_statement

denotes

In many cases, a specific toxic compound cannot be identified.

T917

350162-350308

Epistemic_statement

denotes

Geeldikkop, a disease characterized by hepatogenous photosensitization, is associated with extensive losses among sheep and goats in South Africa.

T918

350451-350592

Epistemic_statement

denotes

Hepatic dicrocoeliosis has been identified as a probable cause of photosensitization affecting a group of 14-month-old ewe lambs in Scotland.

T919

350754-350848

Epistemic_statement

denotes

The pathologic mechanisms underlying the epidermal hyperproliferation are not well understood.

T920

351020-351103

Epistemic_statement

denotes

The lower prostaglandin levels likely reflect a lack of precursor arachidonic acid.

T921

351104-351252

Epistemic_statement

denotes

Deficiency of prostaglandin E 2 could influence epidermal cell kinetics through its effect on ratios of cyclic AMP to guanosine monophosphate (GMP).

T922

351253-351530

Epistemic_statement

denotes

Supplementation of animal diets with balanced omega-6 and omega-3 fatty acids is thought to modulate arachidonic acid metabolism and subsequent production of leukotrienes and prostaglandins that, in turn, may influence epidermal turnover kinetics and the inflammatory response.

T923

351531-351710

Epistemic_statement

denotes

A seborrheic dermatosis in cats, characterized by dry scaly skin and alopecia, is responsive to fatty acid supplementation but is not likely to be the result of a true deficiency.

T924

352139-352275

Epistemic_statement

denotes

Cutaneous lesions may occur as manifestations of deficiencies of vitamins A, C, and E; riboflavin; pantothenic acid; biotin; and niacin.

T925

352344-352523

Epistemic_statement

denotes

Many of the naturally occurring hypovitaminoses are probably not the result of a single vitamin deficiency but represent the cumulative effect of several inadequacies of the diet.

T926

352925-353033

Epistemic_statement

denotes

Vitamin A oversupplementation is teratogenic and can lead to toxicity if liver storage capacity is exceeded.

T927

353151-353260

Epistemic_statement

denotes

Hypovitaminosis A has been reported in all species of domestic animals, although many accounts are anecdotal.

T928

353261-353417

Epistemic_statement

denotes

It may be secondary to dietary deficiency, decreased intestinal absorption, liver disease, or toxicities such as chlorinated naphthalene toxicity of cattle.

T929

353888-354037

Epistemic_statement

denotes

In one syndrome, Cocker Spaniels are predisposed, probably because of a congenital abnormality of epidermopoiesis and keratinization (see Seborrhea).

T930

354109-354349

Epistemic_statement

denotes

Cutaneous manifestations of systemic disease not known to be a result of a nutritional derangement are discussed in other, more appropriate sections of this chapter, such as Endocrine diseases of skin and Cutaneous paraneoplastic syndromes.

T931

354480-354656

Epistemic_statement

denotes

Even though water intake may not be restricted, there is reduced hydration of the connective tissues of the subcutis and dermis, and the skin wrinkles and loses its elasticity.

T932

354657-354778

Epistemic_statement

denotes

As hair is 95% protein, hair growth and keratinization can require up to 25-30% of an animal's daily protein requirement.

T933

354779-354960

Epistemic_statement

denotes

Protein deficiencies are rare but can occur in cats fed primarily food formulated for dogs, in young dogs fed a low-protein diet, or in animals with increased nutrient requirements.

T934

355052-355171

Epistemic_statement

denotes

Hypotrichosis develops as a thinning of the hair rather than baldness, and seasonal shedding may cease or be prolonged.

T935

355172-355245

Epistemic_statement

denotes

Lesions may be symmetrical on the head and trunk and spread to the limbs.

T936

355246-355353

Epistemic_statement

denotes

The skin may atrophy, or hyperkeratosis, hyperpigmentation, and possibly loss of hair pigmentation develop.

T937

355354-355535

Epistemic_statement

denotes

The histopathologic findings in the skin may mimic an endocrinopathy, with severe epidermal and adnexal atrophy, orthokeratotic hyperkeratosis, and telogenization of hair follicles.

T938

356308-356511

Epistemic_statement

denotes

Specific amino acid deficiencies have been investigated as potential replacements for mechanical shearing as wool production is highly dependent upon levels of certain amino acids, specifically cysteine.

T939

356626-356762

Epistemic_statement

denotes

Fatty acid deficiency may occur in all domestic species in association with general dietary deficiency, malabsorption, or liver disease.

T940

356763-356967

Epistemic_statement

denotes

Deficiencies may be evident in animals when the fat has either leached from a diet, has become rancid from improper or prolonged storage, or when the diet was formulated with low fat content to save cost.

T941

356968-357127

Epistemic_statement

denotes

Animals on specially formulated low-fat diets for therapeutic reasons may develop signs of fatty acid deficiency and require specific types of supplementation.

T942

357128-357215

Epistemic_statement

denotes

Animals on antioxidant-deficient diets may also develop signs of fatty acid deficiency.

T943

357419-357536

Epistemic_statement

denotes

Otitis externa may be an accompanying lesion, and the skin is susceptible to secondary bacterial and yeast infection.

T944

357739-357848

Epistemic_statement

denotes

Young preruminant calves may show dermatologic signs that include alopecia, a roughened coat, and dermatitis.

T945

357890-358019

Epistemic_statement

denotes

Biotin deficiency rarely occurs spontaneously, except in intensively reared swine, as the vitamin is widely distributed in feeds.

T946

358090-358203

Epistemic_statement

denotes

Feeding raw egg whites that contain avidin, a substance that renders biotin unavailable, may induce deficiencies.

T947

359010-359106

Epistemic_statement

denotes

Biotin deficiency reportedly causes a dry, brittle, haircoat, scaling, and leukotrichia in dogs.

T948

359107-359294

Epistemic_statement

denotes

Dogs deficient in biotin may develop periocular and facial alopecia resembling the clinical lesions of systemic lupus erythematosus, discoid lupus, or other dermatoses affecting the face.

T949

360430-360603

Epistemic_statement

denotes

Because pyridoxine may be indirectly involved in zinc transport, through its effect on tryptophan metabolism, these effects might be due to alteration in the levels of zinc.

T950

360959-361209

Epistemic_statement

denotes

Insects, invertebrates, and fish also cannot synthesize vitamin C. Deficiencies (scurvy or scorbutus) are limited to these species of animals, and signs are related to the inability of fibroblasts to form collagen or osteoid and are discussed in Vol.

T951

361378-361443

Epistemic_statement

denotes

There may be accompanying ceruminous otitis externa and pyoderma.

T952

361881-361963

Epistemic_statement

denotes

There are rare reports of vitamin A-responsive dermatoses in other breeds of dogs.

T953

362082-362242

Epistemic_statement

denotes

The fact that therapy is effective can be attributed more to the "normalizing" effect of vitamin A (and retinoids) on cellular differentiation in the epidermis.

T954

362331-362406

Epistemic_statement

denotes

Oral supplementation with vitamin A may be needed to confirm the diagnosis.

T955

362407-362521

Epistemic_statement

denotes

The B-vitamin complex is essential to the maintenance and proper functioning of many important metabolic pathways.

T956

362712-362759

Epistemic_statement

denotes

Single deficiencies of these vitamins are rare.

T957

362846-362989

Epistemic_statement

denotes

Riboflavin (vitamin B 2 ) deficiency is mostly a problem in swine and chickens fed grain rations with borderline concentrations of the vitamin.

T958

363078-363171

Epistemic_statement

denotes

Young calves, however, may develop deficiency if deprived of milk or an appropriate replacer.

T959

363619-363686

Epistemic_statement

denotes

Deficiency is documented in pigs, but may occur in dogs and calves.

T960

363687-363862

Epistemic_statement

denotes

Pantothenic acid deficiency in pigs produces progres- demonstration of ceroid, a variant of lipofuscin, which is acid fast and autofluorescent, should establish the diagnosis.

T961

364212-364327

Epistemic_statement

denotes

Alopecia in calves associated with the feeding of milk substitute was attributed, in part, to vitamin E deficiency.

T962

364627-364736

Epistemic_statement

denotes

Naturally occurring true zinc deficiency is rare in dogs, extremely rare in cats, and not reported in horses.

T963

365344-365542

Epistemic_statement

denotes

The relationship between the changes in particular tissue enzyme activities brought about by zinc deficiency and clinical manifestations of the deficiency syndrome are not, however, well understood.

T964

365609-365851

Epistemic_statement

denotes

The parakeratosis seen in cases of zinc deficiency and zinc-responsive dermatosis may be related to decreased activity of zinc-related lytic enzymes along with increased epidermal cell turnover, which results in failure of nuclear hydrolysis.

T965

366176-366240

Epistemic_statement

denotes

There may be erythema, petechiae, and ecchymoses on extremities.

T966

366241-366326

Epistemic_statement

denotes

Severely affected calves may have systemic signs, such as depression and slow growth.

T967

366581-366853

Epistemic_statement

denotes

Steatitis or "yellow-fat disease" involves subcutaneous fat and may be seen clinically as a skin disease, and can result from consumption of high levels of unsaturated fatty acids and/or insufficient vitamin E. The yellowness of the fat is due to the deposition of ceroid.

T968

367013-367087

Epistemic_statement

denotes

Naturally occurring vitamin E deficiency has not been reported in the dog.

T969

367153-367287

Epistemic_statement

denotes

The disease is associated the feeding of fishmeal, fish offal, or other products with a high concentration of unsaturated fatty acids.

T970

367288-367594

Epistemic_statement

denotes

Diets with a high content of oily fish, such as tuna, white fish, and sardines, are most often implicated; however, the condition in cats also has been associated with diets containing primarily pig's brain, liver, diets with only a small fish content, or improperly stored or outdated commercial cat food.

T971

367786-367969

Epistemic_statement

denotes

The disease is not, however, the result of a simple deficiency, because cats fed diets deficient in vitamin E but also lacking in unsaturated fatty acids, do not develop panniculitis.

T972

367970-368215

Epistemic_statement

denotes

In mink and foals, it may be associated with degeneration of muscles, and in swine it may occur alone or be associated with any one or combination of ulceration of the squamous mucosa of the stomach, muscle degeneration, and hepatosis dietetica.

T973

368216-368495

Epistemic_statement

denotes

The disease has variable mortality in cats after a short clinical course in which there is progressive depression, possible fever, hyperesthesia, reluctance to move, and palpable thickening and increased firmness of the subcutaneous fat, easiest to detect in the inguinal region.

T974

368689-368758

Epistemic_statement

denotes

Hematologic changes may include neutrophilic leukocytosis and anemia.

T975

368853-368977

Epistemic_statement

denotes

This, together with a fishy odor, may be all that is observed in swine in which the fat is soft and gray rather than yellow.

T976

369177-369207

Epistemic_statement

denotes

Mineralization may be present.

T977

369208-369286

Epistemic_statement

denotes

Ceroid may be found also in macrophages of the liver, spleen, and lymph nodes.

T978

369287-369540

Epistemic_statement

denotes

In cats, the initial differential should include infectious steatitis, sterile nodular panniculitis, lupus panniculitis, or other noncutaneous diseases, such as feline infectious peritonitis, ascites of various causes, and other causes of hyperesthesia.

T979

369776-369907

Epistemic_statement

denotes

With bacterial infection, there may be nodular or diffuse neutrophilic dermatitis, folliculitis, perifolliculitis, or furunculosis.

T980

370153-370335

Epistemic_statement

denotes

Parakeratosis is rarely fatal unless toxemia or septicemia secondary to cutaneous bacterial infection develop or because of exacerbation of intercurrent infections such as pneumonia.

T981

370514-370548

Epistemic_statement

denotes

The condition is uncommon to rare.

T982

370896-370952

Epistemic_statement

denotes

Drinking water with excessive iron can also be a factor.

T983

370953-371158

Epistemic_statement

denotes

In true zinc deficiency, multiple animals in a herd may be affected and show clinical signs of decreased appetite and growth, weight loss, decreased milk production, depression, stiff joints, and diarrhea.

T984

371546-371588

Epistemic_statement

denotes

Dull, rough, brittle haircoat may be seen.

T985

371611-371652

Epistemic_statement

denotes

In sheep, fleece/wool biting may be seen.

T986

372701-372810

Epistemic_statement

denotes

Zinc deficiency may induce secondary vitamin A deficiency as a result of its effect on appetite and food use.

T987

372811-372950

Epistemic_statement

denotes

Economic losses are due to depression of growth rate, but, with improved management techniques, parakeratosis is no longer a major problem.

T988

373122-373258

Epistemic_statement

denotes

The lesions develop into papules, which become covered with a gray-brown, dry, roughened scale-crust that may reach 5-7 mm in thickness.

T989

373668-373729

Epistemic_statement

denotes

In severely affected animals, lesions may become generalized.

T990

374360-374570

Epistemic_statement

denotes

• Syndrome 2 occurs in puppies of any breed and is associated with a relative deficiency of zinc, probably secondary to excessively high levels of calcium and/or phytates in the diet in rapidly growing animals.

T991

374571-374628

Epistemic_statement

denotes

Excessive iron in the drinking water may also contribute.

T992

374629-374741

Epistemic_statement

denotes

In the United States, this disease sheep, there may be a mix of orthokeratotic and parakeratotic hyperkeratosis.

T993

374873-374948

Epistemic_statement

denotes

The bridge of the nose, muzzle, and periocular region may also be affected.

T994

374977-375142

Epistemic_statement

denotes

In alpacas, it is thought that breeding females and those with darker fleeces are more susceptible to zinc-responsive dermatosis because of a higher demand for zinc.

T995

375143-375338

Epistemic_statement

denotes

Histopathologic findings include papillated epidermal hyperplasia with predominantly orthokeratotic hyperkeratosis, parakeratotic caps, and lymphoeosinophilic superficial perivascular dermatitis.

T996

375835-375916

Epistemic_statement

denotes

Naturally occurring zinc-responsive dermatoses in the dog fall under 2 syndromes:

T997

375917-376054

Epistemic_statement

denotes

• Syndrome 1 affects primarily Siberian Huskies and Alaskan Malamutes, and rarely other breeds not of Arctic origin, such as Great Danes.

T998

376136-376245

Epistemic_statement

denotes

Older dogs may develop lesions during times of stress, such as pregnancy, lactation, or intercurrent disease.

T999

376420-376497

Epistemic_statement

denotes

Lesions may be unilateral initially and progress to a bilateral distribution.

T1000

376498-376522

Epistemic_statement

denotes

Pruritus may be present.

T1001

376559-376616

Epistemic_statement

denotes

The pathogenesis of the syndrome is not well established.

T1002

376617-376816

Epistemic_statement

denotes

Alaskan Malamutes with chondrodysplasia have zinc-responsive spermatozoal defects and reduced zinc absorption from the intestinal tract; malabsorption may be responsible for the dermatologic disease.

T1003

376883-376977

Epistemic_statement

denotes

A severe form of zinc-responsive dermatosis has been documented in a litter of Pharaoh Hounds.

T1004

376978-377067

Epistemic_statement

denotes

A role for oxidative stress has been shown in cases of canine zinc-responsive dermatosis.

T1005

377255-377313

Epistemic_statement

denotes

The change may be indicative of low epidermal zinc levels.

T1006

377370-377608

Epistemic_statement

denotes

Hypoaminoacidemia, the result of sustained gluconeogenesis and increased hepatic catabolism, is documented in both canine and human patients, and it has been postulated that it may deplete epidermal proteins and induce epidermal necrosis.

T1007

377609-377661

Epistemic_statement

denotes

Zinc and fatty acid metabolism may also be deranged.

T1008

377662-377880

Epistemic_statement

denotes

The most likely pathogenesis of abnormal or impaired ability to properly use nutrients and the clinical and histologic similarities of this entity to zincresponsive dermatoses warrant discussion of SND in this section.

T1009

377881-378082

Epistemic_statement

denotes

In dogs, SND has been reported to occur in association with a variety of systemic diseases, including glucagon-secreting tumors of the pancreas, hyperglucagonemia, diabetes mellitus, and liver disease.

T1010

378448-378536

Epistemic_statement

denotes

Diabetes and hyperglucagonemia in some cases could be secondary to hepatic degeneration.

T1011

378605-378754

Epistemic_statement

denotes

Rare reports in cats include a pancreatic carcinoma presumably of endocrine origin and a glucagon-producing primary hepatic neuroendocrine carcinoma.

T1012

378816-379006

Epistemic_statement

denotes

The muzzle, lips, periocular skin, edges of the pinnae, distal extremities, ventrum, and points of pressure or friction, such as the hocks, and the external genitalia are typically affected.

T1013

379554-379640

Epistemic_statement

denotes

As these cells degenerate, clefts and vesicles may form in the outer stratum spinosum.

T1014

379641-379696

Epistemic_statement

denotes

Neutrophils may accumulate to form subcorneal pustules.

T1015

379697-379866

Epistemic_statement

denotes

The stratum corneum is diffusely and markedly parakeratotic and appears hypereosinophilic in comparison to the subjacent pale-staining stratum spinosum of the epidermis.

T1016

379867-379934

Epistemic_statement

denotes

The epithelium of the follicular infundibulum can also be affected.

T1017

380015-380160

Epistemic_statement

denotes

Individual necrotic keratinocytes may be located randomly in the epidermis and make distinction from erythema multiforme difficult in some cases.

T1018

380161-380214

Epistemic_statement

denotes

In SND, the necrotic keratinocytes lack satellitosis.

T1019

380395-380540

Epistemic_statement

denotes

In cases associated with liver disease, the most commonly associated gross lesion is a nodular liver with intervening firm, collapsed parenchyma.

T1020

380889-380967

Epistemic_statement

denotes

However, the pathognomonic epidermal edema may not be present in every biopsy.

T1021

380968-381135

Epistemic_statement

denotes

Differential diagnoses include other has been associated with the feeding of generic dog food, in Britain and Sweden with the feeding of soy- and/or cerealbased diets.

T1022

381618-381697

Epistemic_statement

denotes

Secondary pyoderma may develop, and puppies often show a local lymphadenopathy.

T1023

382061-382266

Epistemic_statement

denotes

Some reports indicate that the keratinization defect was sufficiently severe to induce dyskeratotic changes at all levels of the epidermis, whereas in others, orthokeratotic hyperkeratosis alone was found.

T1024

382267-382457

Epistemic_statement

denotes

Differential diagnoses include superficial necrolytic dermatitis, lethal acrodermatitis, thallium toxicity, and chronic hypersensitivity dermatitis that may look very similar histologically.

T1025

382458-382555

Epistemic_statement

denotes

Dermatophytosis, pemphigus foliaceus, and pyoderma should be considered based upon gross lesions.

T1026

382556-382664

Epistemic_statement

denotes

The signalment, history, lesion distribution, and pathologic changes should help to establish the diagnosis.

T1027

382665-382794

Epistemic_statement

denotes

In some cases, response to dietary changes and/or zinc supplementation may be needed for confirmation of the suspected diagnosis.

T1028

383017-383195

Epistemic_statement

denotes

It is possible that dietary factors other than zinc are involved in some of these diseases, particularly those responding to dietary changes and not just to zinc supplementation.

T1029

383499-383646

Epistemic_statement

denotes

The condition resembles necrolytic migratory erythema, a human paraneoplastic syndrome most often associated with α-cell neoplasms of the pancreas.

T1030

383647-383817

Epistemic_statement

denotes

The pathogenesis of superficial necrolytic dermatitis (SND) is unknown, but hepatic dysfunction and derangement of glucose and amino acid metabolism are clearly involved.

T1031

383818-384001

Epistemic_statement

denotes

Elevated glucagon levels alone are unlikely to be directly responsible for the skin lesions, as both dogs and humans may develop the disease in their absence, and dermatitis is not an

T1032

384002-384028

Epistemic_statement

denotes

Further reading Guillot J, et

T2123

719898-720057

Epistemic_statement

denotes

Sporotrichosis is an uncommon chronic infection usually limited to skin and subcutaneous tissue caused by the opportunist fungal pathogen Sporothrix schenckii.

T2124

721156-721294

Epistemic_statement

denotes

Transmission of the infection from cats to humans has been reported many times, and infected cats pose a significant public health danger.

T2125

721452-721485

Epistemic_statement

denotes

The organism may be be extensive.

T2126

721648-721842

Epistemic_statement

denotes

They are often constricted at their prominent thick septations and may contain single or chains of thick-walled vesicular swellings, 25 µm or more in diameter, that resemble chlamydospores (Fig.

T2127

721854-721965

Epistemic_statement

denotes

The innate brown pigment may not be readily apparent in tissue sections, especially in cases of Alternaria spp.

T2128

721966-722067

Epistemic_statement

denotes

Melanin stains, such as Fontana-Masson, can be used to confirm the presence of melanin in the hyphae.

T2129

722068-722144

Epistemic_statement

denotes

Fungal stains demonstrate the organisms well but can mask the natural color.

T2130

722145-722274

Epistemic_statement

denotes

The etiologic agents are so similar in appearance within tissues that they cannot be identified on the basis of their morphology.

T2131

722342-722432

Epistemic_statement

denotes

Phaeohyphomycosis has been confused with eumycotic mycetomas caused by dematiaceous fungi.

T2132

722433-722606

Epistemic_statement

denotes

The fungi in mycetomas form discrete organized granules, whereas those of phaeohyphomycosis appear as individual hyphae and small aggregates scattered throughout the lesion.

T2133

722607-722741

Epistemic_statement

denotes

The aggregates of hyphae in phaeohyphomycosis may be surrounded by Splendore-Hoeppli material, but this does not constitute a granule.

T2134

723129-723181

Epistemic_statement

denotes

Fibrosis is variable; and necrosis may be extensive.

T2135

723331-723536

Epistemic_statement

denotes

The yeasts appear as round, oval, or elongated ("cigar"-shaped) single or budding cells that measure 2-6 µm or more in diameter for the round and oval forms and 2 × 3 to 3 µ 10 µm for the cigar form ( Fig.

T2136

723547-723644

Epistemic_statement

denotes

The cigar forms are considered characteristic of Sporothrix, but they may not be regularly found.

T2137

723645-723742

Epistemic_statement

denotes

In general, organisms are numerous in lesions from cats and rare in tissues from dogs and horses.

T2138

723743-723831

Epistemic_statement

denotes

However, some reports indicate that visible organisms may be few or absent in some cats.

T2139

723832-723881

Epistemic_statement

denotes

In immunosuppressed dogs, yeasts may be numerous.

T2140

723882-723952

Epistemic_statement

denotes

The yeasts may be extracellular or within neutrophils and macrophages.

T2141

723953-724083

Epistemic_statement

denotes

The yeasts have a refractile cell wall from which the cytoplasm may shrink during processing and give the appearance of a capsule.

T2142

724084-724222

Epistemic_statement

denotes

In such instances and when no cigar forms are evident, the organism may be mistaken for Cryptococcus neoformans or Histoplasma capsulatum.

T2143

724223-724340

Epistemic_statement

denotes

Yeasts stand out clearly with fungal stains, but serial sections may be needed to demonstrate even a single organism.

T2144

724341-724428

Epistemic_statement

denotes

Without a significant number of cigar-shaped forms, identification may not be possible.

T2145

724429-724678

Epistemic_statement

denotes

Tissue culture, immunohistochemistry, or fluorescent antibody staining may be necessary for definitive able to penetrate intact skin because not all patients who develop lesions can recall having wounds or being bitten or scratched by infected cats.

T2146

724679-724828

Epistemic_statement

denotes

The large number of organisms typically present in lesions from cats is thought to be the reason for the transmission of disease from cats to humans.

T2147

724829-724923

Epistemic_statement

denotes

However, even when the lesions in cats had few organisms, transmission to humans has occurred.

T2148

725163-725301

Epistemic_statement

denotes

These cases suggest that factors in addition to absolute numbers of yeasts are involved in the apparent ease of cat-to-human transmission.

T2149

725532-725637

Epistemic_statement

denotes

It is thought that this form results from a high degree of host immunity, preventing spread of infection.

T2150

725638-725728

Epistemic_statement

denotes

Nodules may become ulcerated and associated with seropurulent exudate and crust formation.

T2151

725729-725835

Epistemic_statement

denotes

The normal grooming behavior of cats may result in autoinoculation and spread of lesions to distant sites.

T2152

725836-725886

Epistemic_statement

denotes

The cutaneous form may have a very chronic course.

T2153

725887-726030

Epistemic_statement

denotes

An unusual case of sporotrichosis in a dog consisted of otitis externa characterized by multiple cutaneous nodules that persisted for >5 years.

T2154

726486-726549

Epistemic_statement

denotes

The nodules may break open and discharge seropurulent material.

T2155

726550-726628

Epistemic_statement

denotes

Lesions may cavitate and expose extensive areas of underlying muscle and bone.

T2156

727063-727167

Epistemic_statement

denotes

The initial draining puncture wounds may be indistinguishable from cat-inflicted fight wound infections.

T2157

727168-727318

Epistemic_statement

denotes

• The extracutaneous/disseminated form may involve a single extracutaneous tissue, such as osteoarticular sporotrichosis, or multiple internal organs.

T2158

727416-727544

Epistemic_statement

denotes

The disseminated form of sporotrichosis occurs most frequently in cats, and no immunosuppressive factors are usually identified.

T2159

727762-727798

Epistemic_statement

denotes

This is a rare presentation in dogs.

T2160

728112-728257

Epistemic_statement

denotes

The infective stage of the organism is a biflagellate aquatic zoospore that is released seasonally in association with warm weather and moisture.

T2161

728305-728531

Epistemic_statement

denotes

Infection is thought to be acquired from prolonged contact with stagnant fresh water containing the newly emerged zoospores that are motile and are attracted chemotactically to animal hair, damaged skin, and intestinal mucosa.

T2162

728727-728902

Epistemic_statement

denotes

The body temperature of the host stimulates the encysted zoospores to develop a germ tube (hypha) that extends into the infected tissue and can later infiltrate blood vessels.

T2163

729021-729140

Epistemic_statement

denotes

The zoospore stage is not known to form in tissue, and the infection is thus not considered to have zoonotic potential.

T2164

729141-729327

Epistemic_statement

denotes

Not all animals with pythiosis have a history of contact with permanent bodies of water, suggesting that the organism may proliferate in temporary stands of water or even on wet grasses.

T2165

729443-729690

Epistemic_statement

denotes

Lesions occur most commonly on the limbs, distal to the carpus and hock, and on the ventral aspect of the thorax and abdomen, sites that are most likely to be in contact with stagnant water and would be traumatized by aquatic plants or vegetation.

T2166

730106-730269

Epistemic_statement

denotes

The tracts also contain characteristic gray-white to pale yellow coral-like concretions (called leeches or kunkers) that may be extruded at the skin surface ( Fig.

T2167

730562-730675

Epistemic_statement

denotes

The largest lesions usually develop on the thorax and abdomen and may attain a size of 45 cm or more in diameter.

T2168

730676-730725

Epistemic_statement

denotes

In chronic cases, underlying bone may be invaded.

T2169

730726-730792

Epistemic_statement

denotes

Regional lymph nodes may be involved, but visceral spread is rare.

T2170

730793-730985

Epistemic_statement

denotes

The clinical appearance of the lesions may resemble basidiobolomycosis, cutaneous habronemiasis, excessive granulation tissue, and neoplasia (particularly sarcoid and squamous cell carcinoma).

T2171

731081-731213

Epistemic_statement

denotes

The disease occurs most often in young adult, large-breed dogs, and German Shepherd dogs and Labrador Retrievers may be predisposed.

T2172

731644-731705

Epistemic_statement

denotes

Early lesions on the legs may resemble acral lick dermatitis.

T2173

732462-732536

Epistemic_statement

denotes

Organisms can be difficult to identify microscopically in both conditions.

T2174

733065-733201

Epistemic_statement

denotes

The organisms are thought to enter the skin through cutaneous wounds, and infection may involve the dermis, subcutis, or distant tissue.

T2175

733202-733283

Epistemic_statement

denotes

These organisms are often associated with devastating and often fatal infections.

T2176

733284-733516

Epistemic_statement

denotes

Pythiosis (leeches, kunkers, swamp cancer, bursattee) is a chronic cutaneous-subcutaneous, gastrointestinal, or multisystemic infection of horses, dogs, humans, cattle, cats, and sheep, with rare reports in camels and other species.

T2177

734914-735121

Epistemic_statement

denotes

A moderate to large number of negatively stained hyphae are present at the periphery of the kunkers and may be surrounded by many eosinophils and smaller numbers of lymphocytes, plasma cells, and mast cells.

T2178

735329-735375

Epistemic_statement

denotes

Degenerate or thrombosed arteries may be seen.

T2179

735701-735787

Epistemic_statement

denotes

Most reported cases of pythiosis in cattle have been in beef calves <12 months of age.

T2180

735788-735865

Epistemic_statement

denotes

In sheep, the condition appears to have no age, breed, or sex predisposition.

T2181

736021-736123

Epistemic_statement

denotes

Lesions consist of irregular swellings that may or may not be ulcerated with multiple draining tracts.

T2182

736307-736395

Epistemic_statement

denotes

The lesions may be very painful and lead to recumbency, starvation, and death in calves.

T2183

736396-736460

Epistemic_statement

denotes

However, there have also been reports of spontaneous resolution.

T2184

736461-736546

Epistemic_statement

denotes

Internal spread, especially to lungs, may be more common in sheep than other species.

T2185

736547-736601

Epistemic_statement

denotes

Spontaneous resolution has not been reported in sheep.

T2186

736602-736640

Epistemic_statement

denotes

Reports of pythiosis in cats are rare.

T2187

737175-737451

Epistemic_statement

denotes

In humans and animals, Mucorales organisms tend to cause acute, rapidly progressive disease in immunocompromised individuals, whereas Entomophthorales organisms typically cause localized infections in the subcutaneous tissues or nasal submucosa of immunocompetent individuals.

T2188

737804-737922

Epistemic_statement

denotes

The portal of entry may be cutaneous (via traumatic implantation or biting insects), gastrointestinal, or respiratory.

T2189

738051-738158

Epistemic_statement

denotes

Zygomycosis is a rare disease of humans and animals, including dogs, cats, horses, llamas, sheep, and pigs.

T2190

738596-738657

Epistemic_statement

denotes

Lesions may be unilateral or bilateral, single or multifocal.

T2191

738802-738874

Epistemic_statement

denotes

Small (0.5 mm) foci of yellow friable material (leeches) may be present.

T2192

739348-739489

Epistemic_statement

denotes

The second pattern (granulomatous) consists of epithelioid macrophages and Langerhans giant cells and may be surrounded by connective tissue.

T2193

739490-739535

Epistemic_statement

denotes

Both patterns may be seen in a single lesion.

T2194

739636-739712

Epistemic_statement

denotes

Fibrinoid necrosis of arterial walls and small arterial thrombi may be seen.

T2195

739713-739743

Epistemic_statement

denotes

Angioinvasion is noted rarely.

T2196

740320-740484

Epistemic_statement

denotes

It is readily stained with Gomori methenamine silver (GMS) and appears as thick-walled, sparsely septate hyphae, 2-7 µm in diameter, with occasional branching (Fig.

T2197

740495-740614

Epistemic_statement

denotes

Organisms are usually most numerous in necrotic foci and may also be seen in walls of small arterioles in some species.

T2198

740615-740735

Epistemic_statement

denotes

They are rare in areas of granulomatous inflammation, and they are not usually present in intervening connective tissue.

T2199

740818-740946

Epistemic_statement

denotes

The hyphae of these organisms tend to be broader, ranging from 5-20 µm in diameter; however, the differentiation of Pythium spp.

T2200

741126-741210

Epistemic_statement

denotes

Pythium is readily cultured in most instances, but it cannot be grown in some cases.

T2201

741384-741561

Epistemic_statement

denotes

Not all assays are available for each organism, but a combination of assays and evaluation of the clinical information and laboratory results can lead to a definitive diagnosis.

T2202

741562-741691

Epistemic_statement

denotes

Cutaneous lagenidiosis is remarkably similar to cutaneous pythiosis in geographic occurrence and clinical and histologic lesions.

T2203

741944-742012

Epistemic_statement

denotes

Lesions may be ulcerated with areas of necrosis and draining tracts.

T2204

742013-742139

Epistemic_statement

denotes

Regional lymphadenopathy consisting of granulomatous to pyogranulomatous lymphadenitis is common and may precede skin lesions.

T2205

742140-742277

Epistemic_statement

denotes

The disease can be very aggressive, and affected dogs frequently develop lesions of the great vessels, mediastinum, lungs, and esophagus.

T2206

742341-742389

Epistemic_statement

denotes

Gastrointestinal lesions have not been observed.

T2207

742390-742498

Epistemic_statement

denotes

In some dogs, lesions may be slowly progressive, chronic, and limited to cutaneous and subcutaneous tissues.

T2208

742688-742726

Epistemic_statement

denotes

Pyogranulomatous vasculitis may occur.

T2209

742860-743092

Epistemic_statement

denotes

The microscopic lesions of basidiobolomycosis and conidiobolomycosis are similar to those of pythiosis, and the diseases may be histologically indistinguishable, especially when the width of hyphae is at the narrow end of the range.

T2210

743510-743673

Epistemic_statement

denotes

Thus diagnosis of infection is difficult to make by culture alone and requires histologic demonstration of tissue invasion by morphologically compatible organisms.

T2211

743674-743834

Epistemic_statement

denotes

In humans, these infections are usually associated with immunosuppression and neutropenia, but predisposing factors are only occasionally identified in animals.

T2212

744258-744373

Epistemic_statement

denotes

A. terreus has been associated with subcutaneous granulomas in an adult Holstein cow without any lesions elsewhere.

T2213

744374-744460

Epistemic_statement

denotes

Dogs with disseminated aspergillosis may rarely develop cutaneous lesions secondarily.

T2214

745140-745341

Epistemic_statement

denotes

Piedra is an opportunistic infection and has been associated with cutaneous infections, urinary tract infections, systemic infections, pneumonitis, valvular endocarditis, fatal mastitis, and abortions.

T2215

745842-745928

Epistemic_statement

denotes

Lesions may be associated with exophthalmos and appear as white to yellow firm masses.

T2216

746129-746235

Epistemic_statement

denotes

Subcutaneous zygomycosis caused by Conidiobolus of unknown species has been reported in a young adult dog.

T2217

746903-747006

Epistemic_statement

denotes

Small irregular gritty masses of yellow-white material (kunkers, leeches) may discharge to the surface.

T2218

747286-747478

Epistemic_statement

denotes

The clinical lesions are similar to those of pythiosis but may sometimes be differentiated in the horse by differences in anatomic location, number and appearance of kunkers, and epidemiology.

T2219

747479-747580

Epistemic_statement

denotes

Basidiobolomycosis is a rare cause of pulmonary disease and ulcerative draining skin lesions in dogs.

T2220

747581-747697

Epistemic_statement

denotes

Disseminated infection involving the gastrointestinal tract and other abdominal organs has been described in 2 dogs.

T2221

748136-748330

Epistemic_statement

denotes

Fungi are usually located in necrotic foci and may be seen as clear linear or circular hyphal "ghosts" often surrounded by a thick (2.5-25 µm) eosinophilic sleeve (Splendore-Hoeppli phenomenon).

T2222

748660-748785

Epistemic_statement

denotes

Basophilic granular protoplasm may be visible with H&E stain, but the organisms are usually better visualized with GMS stain.

T2223

748903-748953

Epistemic_statement

denotes

Folded, twisted, or compressed hyphae may be seen.

T2224

749309-749456

Epistemic_statement

denotes

the intermediate hosts is not known, but mechanical transmission by blood-sucking insects is regarded as an important natural mode of transmission.

T2225

749457-749583

Epistemic_statement

denotes

Some studies suggest that direct transmission from intermediate host to intermediate host is possible, such as through mating.

T2226

749737-749843

Epistemic_statement

denotes

Infection, however, may be generalized and is typically so in some infections in rodents and wild animals.

T2227

751010-751137

Epistemic_statement

denotes

In Europe, mortality is <1%, and although many animals in an endemic area may be seropositive, most are subclinically infected.

T2228

751138-751218

Epistemic_statement

denotes

Predilections for age, breed, and sex appear to vary between geographic regions.

T2229

751514-751569

Epistemic_statement

denotes

Infection appear to be rare in calves <6 months of age.

T2230

751641-751808

Epistemic_statement

denotes

The acute stage can be confused with bluetongue or malignant catarrhal fever and is characterized by fever, generalized edema, weakness, anorexia, and lymphadenopathy.

T2231

752043-752113

Epistemic_statement

denotes

Pregnant cows may abort, and bulls may develop orchitis and sterility.

T2232

752324-752509

Epistemic_statement

denotes

Animals lose condition, have decreased milk production, have permanent sterility in some bulls, have significant hide damage, and up to 10% mortality may occur during the chronic stage.

T2233

752510-752533

Epistemic_statement

denotes

Lesions may be painful.

T2234

752968-753083

Epistemic_statement

denotes

It is not certain if new tissue cysts are formed during the chronic stage and how long the cysts persist in cattle.

T2235

753396-753569

Epistemic_statement

denotes

has rarely been reported to cause nasal granulomas in cats and in one cat was reported to cause an ulcerated mass on the distal leg at the site of a previous cat-bite wound.

T2236

754232-754402

Epistemic_statement

denotes

Differentials for protozoal dermatitis should include Besnoitia spp., Leishmania spp., Caryospora spp., Neospora spp., Toxoplasma spp., Sarcocystis spp., and Babesia spp.

T2237

754403-754481

Epistemic_statement

denotes

Cutaneous lesions have also been associated with Theileria infection (see Vol.

T2238

754668-754717

Epistemic_statement

denotes

It is closely related to Toxoplasma and Neospora.

T2239

755095-755290

Epistemic_statement

denotes

A feline definitive host has been identified for B. oryctofelis, B. darling, B. neotomofelis, and B. wallacei, which affects rabbits, opossums, southern plains woodrat, and rodents, respectively.

T2240

755291-755390

Epistemic_statement

denotes

The pathogenesis, life cycle, and route of infection are poorly understood for the 4 Besnoitia spp.

T2241

755521-755730

Epistemic_statement

denotes

In the 4 species in which the definitive host is known to be a felid, sexual reproduction is thought to occur in the intestinal tract of the definitive host, and the sporulated oocysts are passed in the feces.

T2242

756097-756368

Epistemic_statement

denotes

Serologic tests can be used to detect subclinical infections; however, these tests have a low level of specificity, Although some tissue cysts do degenerate and cause inflammation, there is no evidence that besnoitiosis can be reactivated from the chronic to acute stage.

T2243

756369-756556

Epistemic_statement

denotes

This is unlike the biology of rodent Besnoitia spp., where it has been shown that chronic B. jellisoni infection in rodents can be reactivated by experimentally induced immunosuppression.

T2244

757447-757554

Epistemic_statement

denotes

For unknown reasons, some infected donkeys remain healthy, whereas others become cachectic and debilitated.

T2245

757555-757638

Epistemic_statement

denotes

Internal dissemination of tissue cysts has not been reported in equid besnoitiosis.

T2246

757639-757812

Epistemic_statement

denotes

Risk factors for infection in donkeys have been suggested to be young age (most affected donkeys have been <3 years of age) and stressful, crowded, or unhygienic conditions.

T2247

757813-757963

Epistemic_statement

denotes

Caprine besnoitiosis caused by B. caprae is clinically and pathologically similar to bovine besnoitiosis but has only been reported in Iran and Kenya.

T2248

757964-758048

Epistemic_statement

denotes

The prevalence of disease is higher in older goats and rare in goats <1 year of age.

T2249

758904-758975

Epistemic_statement

denotes

These may be separated from the wall by an artifactual shrinkage space.

T2250

759911-760072

Epistemic_statement

denotes

Occasionally, they may be detected in A B C nodular form lacked antigen-presenting cells and had more numerous macrophages containing large numbers of organisms.

T2251

760073-760279

Epistemic_statement

denotes

It has been suggested that the clinical and histologic lesions may be useful in establishing a prognosis for remission in that the character of the lesions that develops reflects epidermal immunocompetence.

T2252

760338-760494

Epistemic_statement

denotes

in dogs has been associated with good response to treatment and reduced antibody titers, which are suggestive of immunocompetence and a favorable prognosis.

T2253

760639-760727

Epistemic_statement

denotes

Lesions are most pronounced on the head, pinnae, and extremities but may be generalized.

T2254

760728-760822

Epistemic_statement

denotes

Involved skin may be hypotrichotic to alopecic, and nasodigital hyperkeratosis may also occur.

T2255

761084-761275

Epistemic_statement

denotes

Papular and nodular lesions are generally nonpainful and nonpruritic and are most common on the ventral abdomen, inner aspect of the pinnae, eyelids, and face but can be anywhere on the body.

T2256

761802-761982

Epistemic_statement

denotes

Orthokeratotic and parakeratotic hyperkeratosis are usually prominent, and the inflammatory infiltrate typically is composed of macrophages with fewer lymphocytes and plasma cells.

T2257

761983-762037

Epistemic_statement

denotes

Multinucleated histiocytic giant cells may be present.

T2258

762627-762743

Epistemic_statement

denotes

Leishmania organisms can often be seen with routine H&E stains; however, they are best visualized with Giemsa stain.

T2259

763016-763208

Epistemic_statement

denotes

Histologically, the perifollicular pattern with granulomatous inflammation and sebaceous gland destruction may need to be differentiated from sebaceous adenitis and sterile granuloma syndrome.

T2260

763209-763352

Epistemic_statement

denotes

Feline leishmaniasis is rare and generally occurs as a cutaneous disease without visceral involvement, although visceral involvement can occur.

T2261

764053-764074

Epistemic_statement

denotes

have been identified.

T2262

765146-765248

Epistemic_statement

denotes

Other modes of transmission have been suggested, such as blood transfusions and vertical transmission.

T2263

765442-765546

Epistemic_statement

denotes

Leishmaniasis can manifest as a subclinical infection, selflimiting disease, or severe systemic illness.

T2264

765547-765667

Epistemic_statement

denotes

A variety of host and parasite factors are likely important in determining whether the host is resistant or susceptible.

T2265

765762-765830

Epistemic_statement

denotes

The disease can occur at any age but is more common in young adults.

T2266

765831-766015

Epistemic_statement

denotes

Studies in mice and dogs indicate that resistance to infection is dependent upon a Th1-type of immune response, whereas susceptibility is associated with a Th2-type of immune response.

T2267

766016-766315

Epistemic_statement

denotes

The alopecic form of the cutaneous disease in the dog has been shown to be associated with fewer organisms and a more appropriate cellular immune response in terms of number of antigen-presenting Langerhans cells, major histocompatibility complex II-positive keratinocytes, and infiltrating T cells.

T2268

766316-766342

Epistemic_statement

denotes

In contrast, dogs with the

T2269

766343-766495

Epistemic_statement

denotes

Toxoplasma gondii, an apicomplexan intracellular coccidian parasite, has been reported rarely as a cause of cutaneous lesions in humans, cats, and dogs.

T2270

766736-766819

Epistemic_statement

denotes

The cat is the definitive host, and most mammals can serve as an intermediate host.

T2271

766820-766912

Epistemic_statement

denotes

Most reports of cutaneous toxoplasmosis have been associated with systemic fatal infections.

T2272

767603-767741

Epistemic_statement

denotes

Caryospora spp., apicomplexan parasites whose primary hosts are reptiles and raptors, rarely cause pyogranulomatous dermatitis in puppies.

T2273

767742-767842

Epistemic_statement

denotes

Immunosuppression and concurrent disease, such as canine distemper, likely play a facilitatory role.

T2274

768154-768271

Epistemic_statement

denotes

Not all stages of the life cycle may be present in tissue sections, precluding a microscopic diagnosis in some cases.

T2275

769145-769253

Epistemic_statement

denotes

Reports in cattle are rare: one cow from Switzerland with L. siamensis and one suspected case from Zimbabwe.

T2276

769813-769877

Epistemic_statement

denotes

Cutaneous lesions may not be associated with systemic infection.

T2277

769878-770037

Epistemic_statement

denotes

Diagnosis can be made through finding the organism on cytologic or histologic evaluation of tissues, PCR, immunohis- A B belonging to the family Chlorellaceae.

T2278

770258-770351

Epistemic_statement

denotes

The 2 most common species associated with infection are Prototheca wickerhamii and P. zopfii.

T2279

770457-770619

Epistemic_statement

denotes

In humans, the cutaneous form is the most common and is thought to be initiated by traumatic implantation, resulting in a protracted and indolent clinical course.

T2280

770754-770929

Epistemic_statement

denotes

In those cases in which the organism was speciated, P. zopfii is most often associated with disseminated disease, whereas the cutaneous form has been caused by P. wickerhamii.

T2281

770930-771102

Epistemic_statement

denotes

Despite widespread distribution of Prototheca spp., the prevalence of infection is very low, and attempts to reproduce infection experimentally have met with mixed success.

T2282

771274-771478

Epistemic_statement

denotes

Most humans with cutaneous protothecosis have a concurrent disease condition that may alter the immune response to the organism; however, immunocompromise has not been documented in most affected animals.

T2283

771696-771740

Epistemic_statement

denotes

Nasal planum depigmentation may be striking.

T2284

771741-771991

Epistemic_statement

denotes

Histologically, there is pyogranulomatous to granulomatous dermatitis and panniculitis with epithelioid macrophages, multinucleated histiocytic giant cells, neutrophils, and lymphoid cells are in variable numbers, and foci of necrosis may be present.

T2285

772434-772649

Epistemic_statement

denotes

Identification of Prototheca can be made reliably by examination of tissue sections, but species identification usually requires culture or immunofluorescence methods because differences in the 2 species are subtle.

T2286

773227-773428

Epistemic_statement

denotes

This parasite is a primary pathogen in dogs and has been associated with progressive ascending paralysis, polymyositis, multifocal central nervous system disease, myocarditis, pneumonia, and hepatitis.

T2287

773429-773555

Epistemic_statement

denotes

Cutaneous lesions occur rarely in adult dogs, often with underlying immunosuppression from drug therapy or concurrent disease.

T2288

773556-773692

Epistemic_statement

denotes

It is not known whether the disease in adult dogs results from a reactivated congenital infection or from a recently acquired infection.

T2289

773902-774051

Epistemic_statement

denotes

Numerous tachyzoites, 4-7 µm × 1.5-5 µm, may be seen in macrophages, keratinocytes, and neutrophils, and rarely in endothelial cells and fibroblasts.

T2290

774313-774448

Epistemic_statement

denotes

An unidentified Sarcocystis-like protozoan was associated with multiple cutaneous abscesses and disseminated visceral lesions in a dog.

T2291

774928-775033

Epistemic_statement

denotes

Infection with Babesia canis and B. gibsoni have been reported to rarely cause cutaneous lesions in dogs.

T2292

775699-775807

Epistemic_statement

denotes

In general, most arthropod bites initially appear as circular, erythematous lesions, 0.5-2.0 cm in diameter.

T2293

775808-775903

Epistemic_statement

denotes

Lesions may progress to focal areas of necrosis with ulceration, alopecia, and crust formation.

T2294

775904-776052

Epistemic_statement

denotes

Histologically, the area of necrosis and inflammation may have a triangular outline with one point of the triangle in the deep dermis or panniculus.

T2295

776204-776240

Epistemic_statement

denotes

Edema and hemorrhage may be present.

T2296

776241-776404

Epistemic_statement

denotes

As the lesion ages, the area may become nodular to form "arthropod-bite granuloma" composed of macrophages, lymphocytes, mast cells, eosinophils, and plasma cells.

T2297

776405-776458

Epistemic_statement

denotes

Lymphoid nodules with follicle formation may develop.

T2298

777347-777622

Epistemic_statement

denotes

Because of the variety of parasitic modes, it is not possible to generalize on the effects of flies on domestic animals, nor, with the exception of a few obligate parasites, is it possible to be specific because there is little information available on primary pathogenicity.

T2299

777623-778137

Epistemic_statement

denotes

Flies adversely affect domestic animals by causing annoyance, by direct toxicity that may be fatal following massive insect attack, by indirect toxicity resulting from the deposition of larva into damaged skin (myiasis), by local irritant effects causing dermatitis that may predispose to secondary bacterial infection or to myiasis, by injection of antigens that induce hypersensitivity reactions, by blood-feeding activities that cause anemia, and by the biological or mechanical transmission of other pathogens.

T2300

778138-778266

Epistemic_statement

denotes

It has been estimated that tabanid flies could transmit 35 pathogens, including equine infectious anemia virus and trypanosomes.

T2301

778278-778398

Epistemic_statement

denotes

have been implicated in the mechanical transmission of anthrax, mastitis, Habronema spp., and conjunctivitis in animals.

T2302

778399-778504

Epistemic_statement

denotes

Stomoxys calcitrans, the stable fly, is thought to be the primary transmitter of habronemiasis in horses.

T2303

779092-779181

Epistemic_statement

denotes

The parasites of concern to us here belong to the 2 large classes, Insecta and Arachnida.

T2304

779417-779526

Epistemic_statement

denotes

For information on biological characters and classification, reference should be made to texts on entomology.

T2305

779868-779984

Epistemic_statement

denotes

London: Chapman and Hall; associated with bites of stable flies (Stomoxys calcitrans) or deer flies (Chrysops spp.).

T2306

780090-780145

Epistemic_statement

denotes

Lesions may be localized to the intermandibular region.

T2307

780227-780338

Epistemic_statement

denotes

Simulid bites may be involved in the pathogenesis of ear papillomas and insect-bite hypersensitivity in horses.

T2308

780418-780515

Epistemic_statement

denotes

Very little is known of the nature of the cutaneous lesions produced in animals by these insects.

T2309

780799-780866

Epistemic_statement

denotes

The wheals are usually transient but may persist for several weeks.

T2310

781038-781186

Epistemic_statement

denotes

Histologically, there may be intraepithelial eosinophilic spongiform pustules or focal areas of epidermal necrosis indicating the penetration point.

T2311

781439-781631

Epistemic_statement

denotes

The injected salivary substances are irritant, and many are allergenic; hypersensitivity reactions probably contribute to the severity of the local lesions caused by a variety of biting flies.

T2312

781857-781939

Epistemic_statement

denotes

Black flies have also been associated with insect-bite hypersensitivity in horses.

T2313

782592-782741

Epistemic_statement

denotes

Fly-worry occasionally induces such apprehension that the animals run aimlessly ("gadding"), and severe injury or death may result from misadventure.

T2314

783417-783477

Epistemic_statement

denotes

biting midges can cause pruritus and restlessness in horses.

T2315

783545-783653

Epistemic_statement

denotes

bites may suffer weight loss as a result of severe pruritus and irritation (see Immune-mediated dermatoses).

T2316

783985-784059

Epistemic_statement

denotes

Mortality may arise from direct toxic effect as well as from misadventure.

T2317

784060-784137

Epistemic_statement

denotes

Death may be the result of urticarial swelling of the head and neck or shock.

T2318

784138-784313

Epistemic_statement

denotes

Many flies are attracted to exhaled carbon dioxide and can occasionally cause death by suffocation of cattle, horses, or other animals when large numbers of flies are inhaled.

T2319

784314-784438

Epistemic_statement

denotes

Mosquitoes, especially aggressive species, such as Aedes vigilex, may cause significant mortality among piglets and puppies.

T2320

784730-784928

Epistemic_statement

denotes

Simuliid flies exert systemic effects through inoculation of a heat-stable toxin, which causes increased vascular permeability and abnormalities in cardiorespiratory function, which may cause death.

T2321

784929-785189

Epistemic_statement

denotes

The hematophagous flies seldom cause serious loss of blood; however, anemia may result from heavy infestations by Haematobia irritans, mosquitoes, the sheep ked Melophagus ovinus, and Stomoxys calcitrans, which may ingest as much as 16 mg of blood per feeding.

T2322

785487-785546

Epistemic_statement

denotes

These lesions are associated with black fly (Simulium spp.)

T2323

785799-785874

Epistemic_statement

denotes

Only the third type is associated with clinical signs of variable pruritus.

T2324

785875-786143

Epistemic_statement

denotes

Both the second and third forms are thought to be In South and Central America, Dermatobia hominis (furuncular myiasis) (order Diptera; family Oestridae; subfamily Cuterebrinae) affects horses, cattle, sheep, goats, pigs, rabbits, and people, and rarely dogs and cats.

T2325

786314-786428

Epistemic_statement

denotes

The larvae then attach to the host and penetrate the skin to form local subcutaneous nodules that can be pruritic.

T2326

787273-787372

Epistemic_statement

denotes

The larvae can penetrate the tender skin of young animals, hence the young are most often affected.

T2327

787941-788087

Epistemic_statement

denotes

In the esophageal lesions, collagen bundles around the first instar larvae of H. lineatum appear fragmented, as if undergoing enzymatic digestion.

T2328

788138-788229

Epistemic_statement

denotes

In the epidural lesions of H. bovis, it is the fat tissue that appears Scott DW, Miller WH

T2329

788230-788324

Epistemic_statement

denotes

Myiasis is the infestation of the tissue of living animals with the larvae of dipterous flies.

T2330

788325-788417

Epistemic_statement

denotes

The larvae are referred to as maggots or grubs and may be facultative or obligate parasites.

T2331

789316-789511

Epistemic_statement

denotes

(order Diptera; family Oestridae; subfamily Cuterebrinae) are obligate parasites of rodents and rabbits, but occasionally aberrant infestations occur in cats and rarely in dogs, pigs, and humans.

T2332

789906-790007

Epistemic_statement

denotes

Wounds heal slowly after larvae are removed or released, and secondary bacterial infection may occur.

T2333

790232-790323

Epistemic_statement

denotes

Larvae may locate in aberrant locations, such as the pharynx, nasal cavity, eye, and brain.

T2334

791080-791126

Epistemic_statement

denotes

The subcutaneous tissues may become cavitated.

T2335

791127-791177

Epistemic_statement

denotes

Muscle may be destroyed and body cavities invaded.

T2336

791178-791265

Epistemic_statement

denotes

Lesions may result in death from shock, debilitation, toxemia, or bacterial septicemia.

T2337

791831-791915

Epistemic_statement

denotes

They may also displace the maggots developing from the eggs laid by the primary fly.

T2338

792156-792255

Epistemic_statement

denotes

The prevalence of the disease tends to follow the rise and fall in the population of primary flies.

T2339

792599-792746

Epistemic_statement

denotes

Lesions may affect the preputial orifice (pizzle strike), particularly in animals with narrow urethral orifices, which predispose to urine soiling.

T2340

792747-792838

Epistemic_statement

denotes

Rams with deep head folds may develop poll strike, possibly predisposed to by fight wounds.

T2341

793699-793811

Epistemic_statement

denotes

The lesions, known as "warbles," may be painful and last for 4-6 weeks, during which the larvae undergo 2 molts.

T2342

794133-794260

Epistemic_statement

denotes

Histologically, the cellular reaction is composed of neutrophils and eosinophils, but may be pyogranulomatous to granulomatous.

T2343

794346-794552

Epistemic_statement

denotes

However, the most intense inflammatory reactions occur at sites of previous migration rather than around the viable larvae, suggesting that in naive hosts the parasites depress any effective host responses.

T2344

794679-794744

Epistemic_statement

denotes

Such enzymes could well ablate the host's inflammatory responses.

T2345

795152-795269

Epistemic_statement

denotes

Once the larvae emerge, the cavity is repaired by fibrosis, but small foreign-body granulomas may persist for months.

T2346

795561-795651

Epistemic_statement

denotes

Larval rupture, either accidental or deliberate, may induce a fatal anaphylactic reaction.

T2347

795652-795775

Epistemic_statement

denotes

This may result from systemic effects of the warble toxin, from type I hypersensitivity reactions or a combination of both.

T2348

795908-795975

Epistemic_statement

denotes

It is most common in sheep and can be of major economic importance.

T2349

796453-796500

Epistemic_statement

denotes

Hence any species of animal can be susceptible.

T2350

796501-796620

Epistemic_statement

denotes

Moisture, whether provided by rain, dew, urine, sweat, or inflammatory exudate, predisposes to bacterial proliferation.

T2351

796718-796821

Epistemic_statement

denotes

H. irritans is also thought to transmit the skin parasitic nematode of cattle, Stephanofilaria stilesi.

T2352

796822-796913

Epistemic_statement

denotes

Haematobia irritans was associated with teat atresia in a herd of Limousin cattle in Texas.

T2353

797324-797402

Epistemic_statement

denotes

Institution of a horn fly control program eliminated the problem in this herd.

T2354

797991-798182

Epistemic_statement

denotes

Lesions of Culicoides hypersensitivity (see Immune-mediated dermatoses) and onchocerciasis may also occur on the ventrum, but these are diffuse, often extending from the axillae to the groin.

T2355

798183-798343

Epistemic_statement

denotes

Both Culicoides hypersensitivity and onchocerciasis are sporadic diseases, whereas up to 80% of horses in a group may be affected with horn fly-bite dermatitis.

T2356

798656-798777

Epistemic_statement

denotes

In cats, mosquito bites can induce a severe papular, crusting dermatitis characterized by dense eosinophilic infiltrates.

T2357

798778-799015

Epistemic_statement

denotes

Experimental studies in cats, by using intradermal skin tests and Prausnitz-Kustner tests, indicate that these lesions develop only in cats hypersensitive to mosquito-bite antigens and are initiated by a type I hypersensitivity reaction.

T2358

799370-799435

Epistemic_statement

denotes

The pinnae may develop symmetrical lesions of miliary dermatitis.

T2359

800465-800602

Epistemic_statement

denotes

The lesions are extremely painful and pruritic and may expand rapidly, leading to death from toxemia and septicemia in untreated animals.

T2360

801195-801291

Epistemic_statement

denotes

They prefer the sides of the neck and body and are difficult to detect in fully fleeced animals.

T2361

801358-801432

Epistemic_statement

denotes

Heavy infestations can lead to anemia and stained wool from fly excrement.

T2362

801584-801669

Epistemic_statement

denotes

Sheep keds can transmit several important infectious agents such as bluetongue virus.

T2363

802190-802284

Epistemic_statement

denotes

Large numbers of horn flies in cattle can urticaria, facial pruritus, angioedema, or necrosis.

T2364

802285-802317

Epistemic_statement

denotes

The tongue may also be involved.

T2365

803122-803284

Epistemic_statement

denotes

Because various species of lice have adapted to different microenvironments within the host pelage, it is possible for an animal to carry several species at once.

T2366

803330-803387

Epistemic_statement

denotes

It tends to be a seasonal problem, being worse in winter.

T2367

803388-803533

Epistemic_statement

denotes

Lice do not breed at temperatures above 30° C and die at temperatures around 50° C. The signs associated with pediculosis are extremely variable.

T2368

804056-804166

Epistemic_statement

denotes

Sucking lice may induce anemia, especially in young animals, that is occasionally fatal in heavy infestations.

T2369

804167-804284

Epistemic_statement

denotes

Weight loss and decreased milk production are associated with the constant irritation seen in some lice infestations.

T2370

804285-804435

Epistemic_statement

denotes

Lice are usually host specific, but Heterodoxus longitarsus, normally parasitic on kangaroos, has become an important ectoparasite of Australian dogs.

T2371

805298-805373

Epistemic_statement

denotes

Nodular eosinophilic granulomas with collagen flame figures may be present.

T2372

805475-805542

Epistemic_statement

denotes

Cats may have regional lymphadenopathy and peripheral eosinophilia.

T2373

806083-806162

Epistemic_statement

denotes

Certain caterpillar larvae can cause cutaneous reactions most commonly in dogs.

T2374

806695-806798

Epistemic_statement

denotes

Hence animals such as ungulates rarely have fleas, and carnivores, rabbits, rodents, and bats often do.

T2375

806799-806842

Epistemic_statement

denotes

Most fleas can parasitize a range of hosts.

T2376

806995-807055

Epistemic_statement

denotes

Fleas are chiefly a problem in cats, dogs, pigs, and humans.

T2377

807056-807167

Epistemic_statement

denotes

Flea bites damage the host by irritation, pruritus, blood loss, and possible transmission of infectious agents.

T2378

807883-808098

Epistemic_statement

denotes

However, infestations also occur with P. irritans (human flea), Leptopsylla segnis (rat flea), Echidnophaga gallinacea (chicken stick-tight flea), Spilopsyllus cuniculi (European rabbit flea), and Ceratophyllus spp.

T2379

808300-808395

Epistemic_statement

denotes

Most species of fleas move freely around their host's body and can be found virtually anywhere.

T2380

809015-809086

Epistemic_statement

denotes

Some animals, despite heavy infestations, remain asymptomatic carriers.

T2381

809087-809354

Epistemic_statement

denotes

Some animals may develop flea-bite dermatitis, which is a reaction to the many irritant substances in the flea's saliva, but the vast majority of lice are commonly found on the poll, pinnae, muzzle, periocular region, neck, brisket, withers, tail, axillae, and groin.

T2382

809692-809806

Epistemic_statement

denotes

One exception is H. eurysternus infestation, which may cause anemia and death in some uniquely susceptible cattle.

T2383

809807-809889

Epistemic_statement

denotes

L. vituli has been associated with severe anemia and mortality in young buffaloes.

T2384

809890-810001

Epistemic_statement

denotes

Sucking lice can serve as vectors of severe diseases, including anaplasmosis, theileriosis, and dermatomycosis.

T2385

810726-810821

Epistemic_statement

denotes

The haircoat of Angora goats may be seriously damaged by the irritation induced by pediculosis.

T2386

811769-811889

Epistemic_statement

denotes

Chewing lice may be more numerous on the rump, dorsal trunk, and neck, and sucking lice on the head, neck, and shoulder.

T2387

812004-812094

Epistemic_statement

denotes

Trichodectes canis may serve as an intermediate host for the tapeworm, Dipylidium caninum.

T2388

812095-812137

Epistemic_statement

denotes

Pediculosis is a rare disease in pet dogs.

T2389

812138-812290

Epistemic_statement

denotes

Breeds with moderately long, fine hair may provide a more favorable environment for lice, and the disease is more prevalent in the cooler winter months.

T2390

812365-812425

Epistemic_statement

denotes

Pediculosis may resemble flea-bite hypersensitivity in dogs.

T2391

812426-812494

Epistemic_statement

denotes

Infestation in the absence of pruritus may be an incidental finding.

T2392

812571-812702

Epistemic_statement

denotes

Infestation may be an incidental finding, or it may be associated with severe pruritus with dermatitis and hair loss over the back.

T2393

812703-812755

Epistemic_statement

denotes

Pediculosis may resemble miliary dermatitis in cats.

T2394

813280-813483

Epistemic_statement

denotes

In general, both parasites and ova have poor viability in the external environment; however, low temperature and high humidity may allow some mites and nymphs to persist in the environment up to 21 days.

T2395

813484-813650

Epistemic_statement

denotes

The disease, which is highly contagious, is transmitted largely by direct contact, but may occur following indirect contact with contaminated objects such as bedding.

T2396

814186-814318

Epistemic_statement

denotes

Scabies is a complex hypersensitivity reaction involving both humoral and cell-mediated components and circulating immune complexes.

T2397

814521-814633

Epistemic_statement

denotes

In undernourished or immuno-compromised individuals, there may be widespread lesions and large numbers of mites.

T2398

814751-814942

Epistemic_statement

denotes

In a herd situation, there may be decreased feed intake, weight loss, decreased milk production, hide and fiber damage, difficulty in breeding, and secondary bacterial infections and myiasis.

T2399

814943-815022

Epistemic_statement

denotes

In some wildlife species, sarcoptic mange is very severe and can lead to death.

T2400

815023-815182

Epistemic_statement

denotes

The cause for this is not completely understood but may be related to scarcity of food and animals spending much less time feeding because of intense pruritus.

T2401

815183-815301

Epistemic_statement

denotes

In addition, severe skin lesions can lead to ulceration, myiasis, secondary bacterial infections, toxemia, and sepsis.

T2402

815470-815511

Epistemic_statement

denotes

Peripheral lymphadenopathy may be marked.

T2403

816149-816242

Epistemic_statement

denotes

Subsequently, a widespread maculopapular eruption appears over the rump, flanks, and abdomen.

T2404

816776-816954

Epistemic_statement

denotes

Finally, the blood-sucking activities of fleas may induce blood loss, iron deficiency anemia in heavily infested animals, particularly in kittens, puppies, or debilitated adults.

T2405

817156-817296

Epistemic_statement

denotes

In Africa, Tunga penetrans, the chigoe flea or jigger, has been associated with swine infestations, although it is chiefly a human parasite.

T2406

817451-817526

Epistemic_statement

denotes

Infestations of the teat canal have been associated with agalactia in sows.

T2407

817527-817571

Epistemic_statement

denotes

Fleas may act as vectors for swinepox virus.

T2408

817726-817778

Epistemic_statement

denotes

Fleas may also trigger allergic dermatitis in sheep.

T2409

817779-817829

Epistemic_statement

denotes

C. felis felis has been rarely reported in cattle.

T2410

817938-818025

Epistemic_statement

denotes

Rarely, horses may become infested with C. felis felis, E. gallinacea, or T. penetrans.

T2411

818214-818257

Epistemic_statement

denotes

Heavily infested animals can become anemic.

T2412

818616-818693

Epistemic_statement

denotes

Most can parasitize people but will not complete their life cycle on a human.

T2413

818802-818912

Epistemic_statement

denotes

Sarcoptic mange is common in pigs, dogs, and goats and is uncommon to rare in cattle, sheep, horses, and cats.

T2414

819289-819411

Epistemic_statement

denotes

The vast majority of dogs have widespread lesions, but some dogs have localized lesions limited to one area of their body.

T2415

819567-819761

Epistemic_statement

denotes

Dogs with compromised immune systems, resulting from coexistent immunosuppressive disease or therapy with corticosteroids or cytotoxic drugs, may be infested by much larger populations of mites.

T2416

819762-819815

Epistemic_statement

denotes

Infestation with S. scabiei can occur rarely in cats.

T2417

820534-820654

Epistemic_statement

denotes

bovis ("head mange"), the lesions chiefly affect the face, pinnae, neck, shoulders, and rump but may become generalized.

T2418

820703-820809

Epistemic_statement

denotes

caprae, causes lesions most commonly on the face, pinnae, neck, and legs but may become generalized ( Fig.

T2419

821153-821177

Epistemic_statement

denotes

equi, is rare in horses.

T2420

821178-821246

Epistemic_statement

denotes

Lesions begin on the head, pinnae, and neck and may spread caudally.

T2421

821756-821848

Epistemic_statement

denotes

Rarely, sections of mites or ova may be present within the epidermis or surface crusts (Fig.

T2422

821989-822145

Epistemic_statement

denotes

In fully developed lesions, there is marked spongiosis, mixed leukocytic exocytosis, serocellular crusts, and possibly intraepidermal eosinophilic pustules.

T2423

822146-822212

Epistemic_statement

denotes

Vasodilation, endothelial swelling, and edema may also be present.

T2424

822739-822943

Epistemic_statement

denotes

Diagnosis of the typical allergic form of the disease depends chiefly on the clinical signs of extreme pruritus and the nature B A These burrows appear on the skin surface in the center of minute papules.

T2425

823092-823143

Epistemic_statement

denotes

There may be accompanying regional lymphadenopathy.

T2426

823379-823439

Epistemic_statement

denotes

Mite segments may be found within the superficial epidermis.

T2427

824028-824196

Epistemic_statement

denotes

There are actually fewer species of psoroptic mites than originally thought, as mites from one host can often infect another host, and morphologic distinctions overlap.

T2428

825070-825236

Epistemic_statement

denotes

Bovine psoroptic mange showed a recrudescence in North America during the 1970s and early 1980s but has been brought under control by the effective use of ivermectin.

T2429

826259-826359

Epistemic_statement

denotes

The disease in cats is uncommon to rare, although there are some endemic areas of higher prevalence.

T2430

826537-826689

Epistemic_statement

denotes

The lesions in cats commence on the head and ears, particularly on the margin of the pinna but may extend to the neck, paw, or become generalized ( Fig.

T2431

826785-826857

Epistemic_statement

denotes

A B calves may develop mild anemia, lymphopenia, and marked neutropenia.

T2432

827223-827302

Epistemic_statement

denotes

Otitis media and otitis interna are possible if the tympanic membrane ruptures.

T2433

827303-827480

Epistemic_statement

denotes

In debilitated or stressed animals, thick brownyellow, dry scale-crust accumulates on the inner aspect of the pinna and, rarely, spreads to involve the poll, body, and the legs.

T2434

827481-827706

Epistemic_statement

denotes

Concurrent Mycoplasma and P. cuniculi infections have been described in the ears of goats; however, Mycoplasma may be cultured from the ears of clinically normal animals, placing some doubt on the significance of the finding.

T2435

828088-828124

Epistemic_statement

denotes

Infested horses may be asymptomatic.

T2436

828225-828265

Epistemic_statement

denotes

Pruritus is variable but can be intense.

T2437

828266-828330

Epistemic_statement

denotes

In mildly pruritic horses, there may be mane and tail seborrhea.

T2438

828438-828594

Epistemic_statement

denotes

P. ovis (P. equi) infestations are rare; lesions are crusted papules with alopecia, and the preferred sites are at the base of the mane, forelock, and tail.

T2439

828698-828791

Epistemic_statement

denotes

The varieties P. auchinae, P. cuniculi, and P. ovis, however, have not been officially named.

T2440

828792-828984

Epistemic_statement

denotes

The condition is usually pruritic, and lesions are most commonly present on the head, neck, and pinnae but can become more widespread, involving the shoulders, back, rump, sides, and perineum.

T2441

828985-829182

Epistemic_statement

denotes

In some cases, clinical signs are limited to the ears and include head shaking, ear twitching, scaling in the ear canals, and occasionally purulent exudate caused by secondary bacterial infections.

T2442

829544-829686

Epistemic_statement

denotes

The detrimental systemic effects may derive directly or indirectly from a chronic hypersensitivity reaction rather than from local dermatitis.

T2443

829687-829872

Epistemic_statement

denotes

The histologic lesions, in which the predominant inflammatory cells in the superficial dermis are eosinophils, mast cells, and lymphocytes, are consistent with an allergic pathogenesis.

T2444

829873-830033

Epistemic_statement

denotes

Constant pruritus resulting from allergy markedly reduces feed intake, and secondary bacterial infection or myiasis may further contribute to loss of condition.

T2445

830034-830151

Epistemic_statement

denotes

There is little evidence to support the hypothesis that the mites inoculate a toxic compound along with their saliva.

T2446

830515-830628

Epistemic_statement

denotes

Eosinophilic microabscesses and focal areas of epidermal edema, leukocytic exocytosis, and necrosis may be found.

T2447

830629-830656

Epistemic_statement

denotes

Dermal edema may be marked.

T2448

830657-830747

Epistemic_statement

denotes

Mites are rarely seen but if present are both on top of and under the surface scale-crust.

T2449

830959-831122

Epistemic_statement

denotes

Psoroptic mange may occur as a latent infection in which mites persist in the ears, infraorbital fossae, inguinal and perineal folds, and at the base of the horns.

T2450

831123-831199

Epistemic_statement

denotes

In rams, mites may be found on the scrotum or prepuce in small, dry lesions.

T2451

831585-831697

Epistemic_statement

denotes

The individual lesions expand at the periphery and may coalesce to become diffuse over most of the body surface.

T2452

831776-831881

Epistemic_statement

denotes

Tufts and clumps of matted wool may be shed or pulled out by self-trauma because of the intense pruritus.

T2453

832040-832212

Epistemic_statement

denotes

In addition, P. cuniculi is an occasional cause of "ear mites" in sheep, and in some cases, clinical signs are limited to the ears and may be due to P. cuniculi or P. ovis.

T2454

832213-832297

Epistemic_statement

denotes

Aural hematomas may result from head shaking, rubbing, and scratching at the pinnae.

T2455

832804-832864

Epistemic_statement

denotes

Infested areas are fairly well defined as areas of alopecia.

T2456

833059-833183

Epistemic_statement

denotes

Eosinophilic epidermal microabscesses and focal epidermal edema, exocytosis, and necrosis ("epidermal nibbles") may be seen.

T2457

833582-833712

Epistemic_statement

denotes

In some cases, lesions may become lichenified, depending upon the duration of the disease and the degree of self-trauma inflicted.

T2458

833966-834015

Epistemic_statement

denotes

Subclinical infections are probably quite common.

T2459

834115-834298

Epistemic_statement

denotes

Chorioptic mange is, in general, a less serious condition than psoroptic mange in cattle, although a syndrome of highly pruritic coronitis was associated with falling milk production.

T2460

834541-834744

Epistemic_statement

denotes

As indicated by the colloquial name "leg mange," lesions occur preferentially on the lower limb around the fetlock but may extend proximally to the thigh and ventral abdomen and rarely become widespread.

T2461

834852-835048

Epistemic_statement

denotes

Lesions are most common on the feet and hindlegs, although lesions can also be on the forelegs, perineum, tail, udder, teats, scrotum, ventrum, and may spread to the lateral trunk, neck, and face.

T2462

835278-835376

Epistemic_statement

denotes

The scrotum may be affected, and the resultant scrotal dermatitis may lead to infertility in rams.

T2463

835377-835445

Epistemic_statement

denotes

Lesions may also be present on the forelegs, udder, teats, and rump.

T2464

835446-835515

Epistemic_statement

denotes

Severe infestations can reduce growth rates and milk and meat yields.

T2465

835844-835948

Epistemic_statement

denotes

Lesions can spread to the axillae, tips and lateral surface of the pinnae, face, neck, dorsum, and feet.

T2466

835949-836015

Epistemic_statement

denotes

In severe cases, erosions, ulcers and lichenification can be seen.

T2467

836016-836147

Epistemic_statement

denotes

Interestingly, heavily infested alpacas can be clinically normal, and alpacas with extensive lesions can have low numbers of mites.

T2468

837257-837422

Epistemic_statement

denotes

They are rapidly killed by desiccation on the surface of the skin, but mites move from follicle to follicle, and it is probably at this time paws, neck, or tailhead.

T2469

837423-837480

Epistemic_statement

denotes

Self-trauma and head shaking can lead to aural hematomas.

T2470

837481-837593

Epistemic_statement

denotes

The mites are contagious, particularly in young animals, and can live off the host for extended periods of time.

T2471

837594-837693

Epistemic_statement

denotes

Diagnosis is by direct visualization; however, mites may be difficult to demonstrate in some cases.

T2472

837694-837776

Epistemic_statement

denotes

Mites can cause a transient papular dermatitis in humans or rarely otitis externa.

T2473

838662-838806

Epistemic_statement

denotes

Adult female mites can live up to 10 and possibly 30 days off their host without feeding, and thus transmission can be both indirect and direct.

T2474

839036-839130

Epistemic_statement

denotes

Lesions often commence over the caudal back and progress cranially but may become generalized.

T2475

839387-839478

Epistemic_statement

denotes

Hair loss may occur because of scratching and overgrooming, and pruritus tends to increase.

T2476

839479-839582

Epistemic_statement

denotes

The intensity of the pruritus may outweigh the number of mites, suggesting a hypersensitivity reaction.

T2477

839583-839724

Epistemic_statement

denotes

Some animals may develop exfoliative erythroderma or a scabies-like condition with similar distribution of lesions and intensity of pruritus.

T2478

839725-839851

Epistemic_statement

denotes

Cats may develop, in addition, focal, multifocal, or generalized erythematous papules or crusted lesions (miliary dermatitis).

T2479

839852-839936

Epistemic_statement

denotes

Other cats may develop selfinduced dorsal hypotrichosis with few or no skin lesions.

T2480

839937-840010

Epistemic_statement

denotes

Freeliving cheyletids (Cheyletus eruditus) can also infest dogs and cats.

T2481

840215-840313

Epistemic_statement

denotes

Cheyletiella eggs and occasionally mites can often be found in feces, especially in grooming cats.

T2482

840683-840952

Epistemic_statement

denotes

Individual human cases of a bullous eruption with systemic lupus erythematosus, bullous pemphigoid, and peripheral eosinophilia with elevated immune complexes and joint pain with decreased mobility and numbing of fingertips associated with C. blakei have been reported.

T2483

841266-841320

Epistemic_statement

denotes

can simultaneously parasitize the same mammalian host.

T2484

841321-841494

Epistemic_statement

denotes

Demodicosis or demodectic mange refers to a proliferation of mites associated with clinical signs and is often, but not always, associated with immunocompromise in the host.

T2485

841762-841939

Epistemic_statement

denotes

Recent genetic studies have demonstrated that D. cornei (the short-tailed mite, 90-148 µm) should be considered a morphologic variant of D. canis rather than a separate species.

T2486

842324-842446

Epistemic_statement

denotes

In some cases, the condition is limited to the external ear canal, and these dogs have pruritic ceruminous otitis externa.

T2487

842664-842745

Epistemic_statement

denotes

Over time, lesions, as described above, enlarge and may coalesce to form patches.

T2488

842746-842781

Epistemic_statement

denotes

Follicular casts may be pronounced.

T2489

842782-842823

Epistemic_statement

denotes

Peripheral lymphadenopathy may be marked.

T2490

843003-843196

Epistemic_statement

denotes

Spontaneous resolution occurs in >50% of cases; however, if lesions do not spontaneously resolve and if the dog does not receive adequate treatment, lesions will likely continue into adulthood.

T2491

843197-843246

Epistemic_statement

denotes

This condition can be very severe and even fatal.

T2492

843370-843531

Epistemic_statement

denotes

Disorders associated with adult-onset demodicosis include hypothyroidism, hyperglucocorticism, leishmaniasis, malignant neoplasia, and immunosuppressive therapy.

T2493

843532-843679

Epistemic_statement

denotes

In >50% of cases, no underlying disease can be documented at the time of demodicosis diagnosis but may become evident weeks to months into therapy.

T2494

843680-843798

Epistemic_statement

denotes

The pathogenesis of juvenile-onset generalized demodecosis appears to be multifactorial and not completely understood.

T2495

843799-843924

Epistemic_statement

denotes

The disease is thought to be a genetically mediated specific immunodeficiency that allows the proliferation of Demodex mites.

T2496

844073-844300

Epistemic_statement

denotes

Although some studies have suggested a decrease in T lymphocytes or premature apoptosis of peripheral blood leukocytes, most dogs are not lymphopenic, and rather, the problem is depressed T-cell function, not decreased numbers.

T2497

844301-844393

Epistemic_statement

denotes

It also appears that immune suppression is worse in those with secondary bacterial pyoderma.

T2498

844565-844681

Epistemic_statement

denotes

IL-10 can inhibit cytokine secretion by Th1 cells, including IL-1, interferon-γ (IFN-γ) and tumor necrosis factor-β.

T2499

845279-845421

Epistemic_statement

denotes

Erythema, hyperpigmentation, and comedones have been described, but hypotrichosis, alopecia, and secondary bacterial skin infections are rare.

T2500

846502-846547

Epistemic_statement

denotes

The external root sheath may be hyperplastic.

T2501

846548-846714

Epistemic_statement

denotes

Current research suggests lymphocytemediated follicular wall injury may be directed against keratinocytes expressing either altered self-antigens or Demodex antigens.

T2502

846715-846920

Epistemic_statement

denotes

It is not known whether or not the presence of cytotoxic T lymphocytes indicates an appropriate host reaction to eliminate the parasite or if it represents an inappropriate and self-damaging host response.

T2503

847054-847115

Epistemic_statement

denotes

Mast cells and eosinophils may be present in smaller numbers.

T2504

847116-847229

Epistemic_statement

denotes

Marked follicular hyperkeratosis is associated with variable numbers of mites in the upper third of the follicle.

T2505

847230-847382

Epistemic_statement

denotes

Mural folliculitis is also consistently present at later stages and in cases with secondary bacterial infection, but may not be the predominant pattern.

T2506

847383-847516

Epistemic_statement

denotes

In some cases, follicles may contain numerous mites but have no evidence of folliculitis, possibly indicating a poor immune response.

T2507

848681-848827

Epistemic_statement

denotes

Mites or fragments of mites are found in the subcapsular zone of regional lymph nodes associated with a local granulomatous inflammatory response.

T2508

848932-849133

Epistemic_statement

denotes

Through blood and lymph drainage, dead and degenerate mites in all stages can also be found in the spleen, lung, intestinal wall, liver, kidney, urinary bladder, thyroid gland, blood, urine, and feces.

T2509

849603-849673

Epistemic_statement

denotes

Three species of Demodex mites are associated with feline demodecosis.

T2510

849674-849758

Epistemic_statement

denotes

D. gatoi appears to be the most common, and it is the shortest, measuring 91-108 µm.

T2511

850056-850262

Epistemic_statement

denotes

It has been found along hair shafts of plucked hairs and therefore is thought to reside Typical gross lesions are multiple cutaneous papules or nodules varying in number from a few to several hundred ( Fig.

T2512

850454-850591

Epistemic_statement

denotes

The preferred sites are the shoulders, neck, dewlap, and muzzle, but in heavy infestations, nodules may be present over most of the body.

T2513

850686-850846

Epistemic_statement

denotes

The contents may liquefy and discharge to the surface, forming a thick crust, or rupture of the nodule into the dermis may generate a pyogranulomatous reaction.

T2514

850847-850976

Epistemic_statement

denotes

Lesions are neither painful nor pruritic, and there may be a seasonal increase in the number of lesions in the spring and summer.

T2515

851150-851244

Epistemic_statement

denotes

Adult parasites occur occasionally in sebaceous glands and rarely in epitrichial sweat glands.

T2516

851245-851319

Epistemic_statement

denotes

A mild mononuclear cell infiltrate may occur around the epithelial lining.

T2517

851320-851546

Epistemic_statement

denotes

Rupture of a follicular cyst induces a marked nodular granulomatous reaction in which degenerating and occasionally mineralized segments of within hair follicles; however, this mite has not been demonstrated in biopsy samples.

T2518

851547-851692

Epistemic_statement

denotes

Demodex gatoi is a contagious mite that is most commonly associated with pruritus and overgrooming; however, some cats are asymptomatic carriers.

T2519

851811-851924

Epistemic_statement

denotes

The skin may be erythematous, scaly, or hyperpigmented, depending on the chronicity and severity of the pruritus.

T2520

851925-851990

Epistemic_statement

denotes

The mite may be difficult to find in cats that groom excessively.

T2521

852041-852170

Epistemic_statement

denotes

The epidermis may be irregularly hyperplastic, and hyperkeratotic and mites can sometimes be observed within the stratum corneum.

T2522

852171-852361

Epistemic_statement

denotes

In severely pruritic cases, there may be erosions, ulcerations, and crusts with mild to moderate perivascular to diffuse infiltrates of lymphocytes, histiocytes, eosinophils, and mast cells.

T2523

852508-852594

Epistemic_statement

denotes

Localized disease is rare and can involve the eyelids, periocular area, head, or neck.

T2524

852595-852637

Epistemic_statement

denotes

It can occur as ceruminous otitis externa.

T2525

852638-852747

Epistemic_statement

denotes

Skin lesions are variably pruritic with patchy alopecia, papules, comedones, erythema, scaling, and crusting.

T2526

852748-852832

Epistemic_statement

denotes

Generalized feline demodicosis is rare and not usually as severe as the canine form.

T2527

852833-852918

Epistemic_statement

denotes

Lesions are primarily on the face and head, but may be on the neck, trunk, and limbs.

T2528

852919-853179

Epistemic_statement

denotes

Generalized demodicosis caused by D. cati is usually associated with underlying disease, such as diabetes mellitus, hyperglucocorticism, feline immunodeficiency virus, or feline leukemia virus, which presumably suppresses normal cell-mediated immune responses.

T2529

853998-854044

Epistemic_statement

denotes

Mites have not been noted on biopsy specimens.

T2530

854553-854773

Epistemic_statement

denotes

In some parts of Africa and Madagascar, demodectic mange in cattle may become generalized and fatal, with this outcome contributed to by other debilitating conditions, such as malnutrition, tick-worry, and tropical heat.

T2531

855027-855076

Epistemic_statement

denotes

This animal died despite antiparasitic treatment.

T2532

855078-855226

Epistemic_statement

denotes

A horses, and llamas with follicular demodecosis, manually squeezing the skin lesions with deep skin scrapings may be necessary to recover the mite.

T2533

855227-855336

Epistemic_statement

denotes

In dogs with D. injai, multiple deep scrapes may need to be performed because mite numbers are generally low.

T2534

855337-855407

Epistemic_statement

denotes

In cats with D. gatoi, multiple surface scrapings should be performed.

T2535

855408-855455

Epistemic_statement

denotes

Mites may also be recovered on fecal flotation.

T2536

855456-855576

Epistemic_statement

denotes

In highly pruritic cats, mites may be difficult to recover, and therefore a treatment trial may help make the diagnosis.

T2537

855577-855719

Epistemic_statement

denotes

In those species with nodular demodicosis (cattle, goats, sheep, pigs), nodules can be incised or manually expressed to reveal multiple mites.

T2538

855720-855815

Epistemic_statement

denotes

Skin scrapings may reveal cigar-shaped larvae, nymphs, and adult mites or elongated ovoid eggs.

T2539

855885-855975

Epistemic_statement

denotes

In dogs, PCR techniques can be used to make a definitive diagnosis regarding mite species.

T2540

856610-856865

Epistemic_statement

denotes

Intensely pruritic dermatitis develops at the sites of attachment, probably as a result of an allergic reaction to the salivary secretions delivered through the stylostome; the allergic reaction caused by larval trombiculid mites is known as trombidiosis.

T2541

856866-857019

Epistemic_statement

denotes

Wild vertebrates are the usual hosts for the trombiculid mite larvae, but food-producing domestic animals, pets, and humans may be accidentally infested.

T2542

857020-857175

Epistemic_statement

denotes

The disease tends to have a seasonal incidence, occurring in the late summer and autumn when climatic conditions favor an expansion of the mite population.

T2543

857176-857376

Epistemic_statement

denotes

Factors such as soil type also influence the parasites and keratin debris are surrounded by epithelioid macrophages, multinucleated histiocytic giant cells, lymphocytes, plasma cells, and eosinophils.

T2544

857721-857788

Epistemic_statement

denotes

Demodectic mange, caused by D. ovis and D. aries, is rare in sheep.

T2545

857881-857968

Epistemic_statement

denotes

Widespread lesions and secondary bacterial infections may be seen in debilitated sheep.

T2546

858267-858343

Epistemic_statement

denotes

D. ovis infestation has been associated with matted fleece ("stringy wool").

T2547

858496-858593

Epistemic_statement

denotes

are found commonly in the Meibomian glands of the horse, demodectic mange is a very rare disease.

T2548

858697-858863

Epistemic_statement

denotes

In horses, demodecosis has been reported in association with chronic treatment with systemic glucocorticoids and in horses with pituitary pars intermedia dysfunction.

T2549

859014-859087

Epistemic_statement

denotes

Lesions occur on the head, neck, and shoulder but may become generalized.

T2550

859261-859396

Epistemic_statement

denotes

Inflammation may be minimal up to various degrees of perifolliculitis, folliculitis, furunculosis, and foreignbody granuloma formation.

T2551

859606-859681

Epistemic_statement

denotes

Proliferation of mites is thought to be due to concurrent immunocompromise.

T2552

859905-859965

Epistemic_statement

denotes

Follicular hyperkeratosis with comedo formation may develop.

T2553

860102-860166

Epistemic_statement

denotes

Rarely, demodicosis has been described in alpacas and one llama.

T2554

860743-860849

Epistemic_statement

denotes

Definitive diagnosis can be made by history, physical examination, and identification of the Demodex mite.

T2555

861554-861693

Epistemic_statement

denotes

The infestation is not usually associated with lesions, although crusted, exudative, and pruritic lesions and alopecia have been described.

T2556

861832-861906

Epistemic_statement

denotes

The parasite may occasionally infest mammals, causing pruritic dermatitis.

T2557

861907-861970

Epistemic_statement

denotes

Mildly pruritic lesions may develop in horses fed infested hay.

T2558

861971-862076

Epistemic_statement

denotes

Multiple papules and wheals may occur on the muzzle, neck, withers, legs, and ventral thorax and abdomen.

T2559

862113-862249

Epistemic_statement

denotes

(Tyroglyphus) longior may cause a pruritic, exudative, crusting, and alopecic dermatosis in horses exposed to contaminated grain or hay.

T2560

862250-862366

Epistemic_statement

denotes

Horses, cattle, goats, cats, and dogs may be infested on rare occasions with the poultry mite, Dermanyssus gallinae.

T2561

862838-862947

Epistemic_statement

denotes

Ornithonyssus syviarum, the northern fowl mite, is another blood-sucking parasite that can parasitize horses.

T2562

862948-862996

Epistemic_statement

denotes

Adult mites can live off the host for 1-3 weeks.

T2563

863148-863270

Epistemic_statement

denotes

House-dust mites, Dermatophagoides farinae and D. pteronyssinus, are associated with allergic dermatitis in dogs and cats.

T2564

863271-863368

Epistemic_statement

denotes

Sheep may, on rare occasions, become infested with the stored-product mite, Sancassania berlesei.

T2565

864302-864342

Epistemic_statement

denotes

Pruritus is variable but can be intense.

T2566

864343-864448

Epistemic_statement

denotes

Different responses to the infestations may be due to individual hypersensitivity reactions to the mites.

T2567

864732-864798

Epistemic_statement

denotes

Lesions may also occur on the muzzle, nares, face, ears, and neck.

T2568

864799-864831

Epistemic_statement

denotes

Horses may sneeze or head-shake.

T2569

864832-864999

Epistemic_statement

denotes

In cats, lesions affect the paws, head, ears, and ventrum, but an atypical generalized form of the disease may occur in association with Walchia americana infestation.

T2570

865526-865610

Epistemic_statement

denotes

Pruritus induces marked self-trauma, which may incite secondary bacterial infection.

T2571

865611-865716

Epistemic_statement

denotes

Histologically, the mite may be present in tunnels within the stratum spinosum or in the stratum corneum.

T2572

865812-865965

Epistemic_statement

denotes

The stylostome appears as a pale staining, hyalinized tube with undulating margins oriented vertical to the skin's surface and extending into the dermis.

T2573

866319-866370

Epistemic_statement

denotes

The ventral thorax and abdomen are rarely involved.

T2574

866887-866908

Epistemic_statement

denotes

Eosinophils are rare.

T2575

867871-867908

Epistemic_statement

denotes

have been described in dogs and cats.

T2576

868120-868322

Epistemic_statement

denotes

In North America, "seed tick infestation" has been associated with Amblyomma americanum larvae, and in Australia "scrub itch" has been associated with I. holocyclus and Haemaphysalis longicornis larvae.

T2577

868881-868937

Epistemic_statement

denotes

Crusts, erosions, ulcerations, and alopecia may develop.

T2578

869610-869684

Epistemic_statement

denotes

In some cases, especially horses, there may be persistent nodular lesions.

T2579

869809-869890

Epistemic_statement

denotes

Lymphoid nodules with developing follicles, resembling pseudolymphoma, may occur.

T2580

870157-870323

Epistemic_statement

denotes

Ticks are small, attach firmly to their hosts, use multiple hosts, live for prolonged periods of time, and can often survive without feeding for long periods of time.

T2581

870324-870475

Epistemic_statement

denotes

These factors make ticks important in the possible transport and transmission of diseases from one host to another and between countries or continents.

T2582

870476-870578

Epistemic_statement

denotes

Importation of animals harboring ticks can pose a threat to animals in areas free of certain diseases.

T2583

870772-870819

Epistemic_statement

denotes

If infestation is heavy, fatalities may result.

T2584

870820-870972

Epistemic_statement

denotes

The local injury may predispose to myiasis and secondary bacterial infection, particularly to staphylococcal cutaneous abscesses or septicemia in lambs.

T2585

871243-871297

Epistemic_statement

denotes

Tick bites may also induce hypersensitivity reactions.

T2586

871676-871922

Epistemic_statement

denotes

Twelve ixodid species have been associated with tick paralysis, and they include Ixodes rubicundus and Rhipicephalus evertsi of South Africa, I. holocyclus of Australia, and R. sanguineus, Dermacentor andersoni and D. variabilis in North America.

T2587

871923-872012

Epistemic_statement

denotes

These ticks have neurotoxins in salivary secretions that can cause paralysis of the host.

T2588

872013-872092

Epistemic_statement

denotes

It may be secreted by the ovaries because it is associated with egg production.

T2589

872093-872188

Epistemic_statement

denotes

The Argasidae are the so-called soft ticks, lacking the scutum that characterizes the Ixodidae.

T2590

872380-872468

Epistemic_statement

denotes

Included those helminthic infestations that remain more or less localized to the dermis.

T2591

873202-873236

Epistemic_statement

denotes

Lesions are consistently pruritic.

T2592

873567-873695

Epistemic_statement

denotes

As a rule, those infective larvae that can invade percutaneously are not host specific, thus infection of aberrant hosts occurs.

T2593

874706-874833

Epistemic_statement

denotes

There the larvae produce acutely inflamed, serpiginous, vesicular to papular tracts that may advance several centimeters a day.

T2594

875490-875550

Epistemic_statement

denotes

A. caninum can complete its life cycle via skin penetration.

T2595

875551-875689

Epistemic_statement

denotes

Although U. stenocephala rarely completes its life cycle via this route, it can produce marked dermatitis as a result of skin penetration.

T2596

876114-876193

Epistemic_statement

denotes

The footpads and interdigital regions of the feet may be edematous and painful.

T2597

876194-876221

Epistemic_statement

denotes

Claw deformities may occur.

T2598

876368-876457

Epistemic_statement

denotes

Larval tracts may be present in the epidermis or dermis lined by degenerating leukocytes.

T2599

876458-876543

Epistemic_statement

denotes

Inflammation is thought to be due to a hypersensitivity reaction to migrating larvae.

T2600

876623-876680

Epistemic_statement

denotes

B. trigonocephalum can cause a similar syndrome in sheep.

T2601

879545-879609

Epistemic_statement

denotes

The lesions are mildly pruritic, and rubbing may aggravate them.

T2602

879610-879697

Epistemic_statement

denotes

In the healing stage, the affected areas remain as alopecic, lichenified plaques ( Fig.

T2603

879708-879852

Epistemic_statement

denotes

Histologically, sections of adult parasites may be seen in the cystic diverticula from hair follicles or lying free in the adjacent dermis (Fig.

T2604

879863-879909

Epistemic_statement

denotes

They may be identified as Stephanofilaria spp.

T2605

880226-880308

Epistemic_statement

denotes

Ulcerative diseases initiated by other causes can be complicated by habronemiasis.

T2606

880494-880600

Epistemic_statement

denotes

Lesions may be single or multiple and range in size from 5-15 cm in diameter and from 0.5-1.5 cm in depth.

T2607

881387-881515

Epistemic_statement

denotes

The entire conjunctiva may be affected, resulting in profuse lacrimation, photophobia, chemosis, and inflammation of the eyelid.

T2608

881633-881725

Epistemic_statement

denotes

Involvement of the penis and prepuce may cause prolapse of the urethral process and dysuria.

T2609

881726-881788

Epistemic_statement

denotes

On rare occasions, Habronema granulomas are found in the lung.

T2610

881789-881963

Epistemic_statement

denotes

Gross lesions of cutaneous habronemiasis may resemble those of exuberant granulation tissue, bacterial pseudomycetoma, pythiosis, equine sarcoid, and squamous cell carcinoma.

T2611

881964-882187

Epistemic_statement

denotes

Habronemiasis may complicate a pre-existing lesion; secondary Habronema infestations occur with pythiosis, Corynebacterium pseudotuberculosis infection, and in skin tumors, particularly squamous cell carcinoma of the penis.

T2612

882466-882596

Epistemic_statement

denotes

Palisading granulomas containing epithelioid macrophages and multinucleated histiocytic giant cells may develop around these foci.

T2613

883555-883652

Epistemic_statement

denotes

PCR may help confirm the diagnosis if larvae are not visible within cytology or biopsy specimens.

T2614

883927-884068

Epistemic_statement

denotes

However, the widespread use of avermectins has dramatically reduced the incidence, and in some areas, cutaneous onchocerciasis is quite rare.

T2615

884185-884332

Epistemic_statement

denotes

In dogs, onchocerciasis has been associated with nodular lesions of the palpebral conjunctiva, third eyelid, sclera, cornea, and retrobulbar space.

T2616

884458-884611

Epistemic_statement

denotes

Cutaneous onchocerciasis is thought to represent a hypersensitivity reaction to microfilarial antigens, and most cases are associated with O. cervicalis.

T2617

884612-884679

Epistemic_statement

denotes

Dead and dying microfilariae provoke the most intense inflammation.

T2618

884680-884760

Epistemic_statement

denotes

O. cervicalis can invade ocular tissues, and these lesions are discussed in Vol.

T2619

884833-884883

Epistemic_statement

denotes

Clinical signs are rare in horses <2 years of age.

T2620

885149-885239

Epistemic_statement

denotes

It is likely that onchocerciasis and Culicoides hypersensitivity can exist simultaneously.

T2621

885553-885710

Epistemic_statement

denotes

Cutaneous lesions include partial or complete alopecia, if ova rather than larvae are found, it is more likely for the parasite to be of the genus Rhabditis.

T2622

885711-885900

Epistemic_statement

denotes

Microfilariae occur free in the dermis or in dermal lymphatics, enclosed within their own vitelline membranes (S. stilesi), or may be found free or unhatched in surface exudate (S. kaeli) .

T2623

886400-886576

Epistemic_statement

denotes

Spongiform microabscesses containing eosinophils and mononuclear cells are also described; such lesions are more typically associated with the bites of arthropod ectoparasites.

T2624

886577-886734

Epistemic_statement

denotes

It is difficult to assess the relative contributions made to the lesion by the stephanofilarial parasite and by the bites of the fly that acts as the vector.

T2625

886938-886969

Epistemic_statement

denotes

Stephanofilaria boomkeri n. sp

T2626

886970-887172

Epistemic_statement

denotes

Oxyuris equi infection of the equine cecum and colon can be associated with pruritic dermatitis of the perineal region, leading to self-induced excoriations and alopecia of the tail known as "rat tail."

T2627

887173-887312

Epistemic_statement

denotes

The adult female parasite crawls out of the anus to deposit eggs on the hair and skin using a gelatinous material that can induce pruritus.

T2628

888494-888537

Epistemic_statement

denotes

Secondary subcutaneous abscesses may occur.

T2629

888702-888775

Epistemic_statement

denotes

Microfilariae may be present in large numbers or may be very sparse (Fig.

T2630

888963-889149

Epistemic_statement

denotes

It is important to note that microfilariae can be seen in skin of normal horses, and thus histopathologic findings should be correlated with historical and physical examination findings.

T2631

889150-889254

Epistemic_statement

denotes

Microfilariae are best recovered from unfixed biopsies that are minced and incubated in saline at 37° C.

T2632

889255-889345

Epistemic_statement

denotes

Viable adult parasites in the nuchal ligament are not associated with significant lesions.

T2633

889346-889485

Epistemic_statement

denotes

In older horses, there is an increased frequency of caseated, mineralized, and granulomatous lesions associated with death of the parasite.

T2634

889649-889787

Epistemic_statement

denotes

They are usually encased in a chronic, fibrosing, and pyogranulomatous to granulomatous mass that may also have dystrophic mineralization.

T2635

889788-889867

Epistemic_statement

denotes

Adult O. gutturosa may also be associated with a similar inflammatory response.

T2636

889982-890032

Epistemic_statement

denotes

Cattle can be infected by 3 species of Onchocerca.

T2637

890163-890290

Epistemic_statement

denotes

Lesions may be hard or soft, depending on the degree of mineralization and fibrosis or the degree of caseation and suppuration.

T2638

891240-891350

Epistemic_statement

denotes

Nematodes of the genus Rhabditis are associated with otitis externa in cattle living in tropical environments.

T2639

891528-891591

Epistemic_statement

denotes

It has been introduced into America, the West Indies, and Fiji.

T2640

891817-891923

Epistemic_statement

denotes

Infection is particularly prevalent in raccoons and mink that appear to be the natural definitive species.

T2641

891924-892008

Epistemic_statement

denotes

The intermediate host is a crustacean copepod, but frogs may act as paratenic hosts.

T2642

892290-892389

Epistemic_statement

denotes

The mature female may measure up to 70 cm in length, resulting in the formation of a 2-4 cm nodule.

T2643

893058-893136

Epistemic_statement

denotes

Ulcerated lesions are seen as draining tracts that may be painful or pruritic.

T2644

893137-893192

Epistemic_statement

denotes

The parasite can be identified by morphologic features.

T2645

894031-894145

Epistemic_statement

denotes

Pelodera dermatitis occurs most commonly in dogs, occasionally in cattle, and rarely in horses, sheep, and humans.

T2646

894146-894266

Epistemic_statement

denotes

Although most reported cases are sporadic, outbreaks involving multiple animals have been described in cattle and sheep.

T2647

894267-894456

Epistemic_statement

denotes

These worms live as saprophytes in warm moist soil that is rich in organic matter, and significant infestations probably require that the host's skin should be continually moist and filthy.

T2648

894518-894610

Epistemic_statement

denotes

Pruritus is moderate to marked in most species, but is variable and can be absent in cattle.

T2649

894892-894933

Epistemic_statement

denotes

Pustules may occur, particularly in dogs.

T2650

894983-895029

Epistemic_statement

denotes

Affected sheep may have complete loss of wool.

T2651

895636-895679

Epistemic_statement

denotes

The remainder of the life cycle is unknown.

T2652

896101-896205

Epistemic_statement

denotes

Schistosoma cercariae can penetrate the skin of many warm-blooded abnormal hosts and produce dermatitis.

T2653

896313-896490

Epistemic_statement

denotes

Canine juvenile cellulitis (juvenile sterile granulomatous dermatitis, puppy strangles, juvenile pyoderma) is an idiopathic disease typically affecting puppies <4 months of age.

T2654

896491-896803

Epistemic_statement

denotes

The cause and pathogenesis are unknown; however, heritability is supported by the fact that the condition is seen more commonly in certain breeds, such as the Golden Retriever, Dachshund, Gordon Setter, Labrador Retriever, and Lhasa Apso, and the condition is sometimes seen in more than one puppy from a litter.

T2655

897074-897243

Epistemic_statement

denotes

Given the young age of onset, some have suggested vaccine reaction as a possible cause; however, reproduction of the disease with subsequent vaccinations does not occur.

T2656

897244-897378

Epistemic_statement

denotes

Depressed in vitro lymphocyte blastogenesis responses have been reported but likely represent the result not the cause of the disease.

T2657

897666-897780

Epistemic_statement

denotes

Strongyloides papillosus can cause pruritic dermatitis of the feet, legs, and ventrum of cattle, goats, and sheep.

T2658

897993-898021

Epistemic_statement

denotes

has been reported in 2 cats.

T2659

898221-898335

Epistemic_statement

denotes

Dirofilaria immitis microfilariae can occasionally lead to cutaneous lesions in dogs harboring the adult parasite.

T2660

899007-899289

Epistemic_statement

denotes

In addition, a generalized cutaneous syndrome characterized by a pruritic papular and crusting dermatitis without intralesional microfilariae has been apparently associated with infection with D. immitis and was thought to be a manifestation of an unusual hypersensitivity reaction.

T2661

899394-899525

Epistemic_statement

denotes

Dirofilaria repens can cause subcutaneous dirofilariasis in dogs, cats, and wild carnivores in Europe and parts of Africa and Asia.

T2662

899782-899864

Epistemic_statement

denotes

Adult nematodes are rarely found but are occasionally recovered from skin nodules.

T2663

900052-900336

Epistemic_statement

denotes

Generally, it is not associated with clinical signs; however, there is one report of 10 dogs with an Acanthocheilonema-like parasite showing single to multiple pruritic papules and plaques with alopecia, scarring, erythema, ulceration, and crusting over the head, neck, and shoulders.

T2664

901062-901247

Epistemic_statement

denotes

The lesion described in the dermis of dogs is erythematous papular and pruritic dermatitis with perivascular to A B has also been reported in adult dogs; however, this is controversial.

T2665

901539-901635

Epistemic_statement

denotes

Lymphadenopathy of the mandibular nodes is common and may precede the onset of the skin lesions.

T2666

901636-901747

Epistemic_statement

denotes

Lymphadenitis may also occur in nodes distant to the skin lesions and may occur in the absence of skin lesions.

T2667

901826-901973

Epistemic_statement

denotes

Some puppies develop concurrent sterile pyogranulomatous panniculitis with firm to fluctuant subcutaneous nodules that may develop draining tracts.

T2668

902052-902085

Epistemic_statement

denotes

Lameness and paresis can be seen.

T2669

902341-902406

Epistemic_statement

denotes

Sebaceous glands and epitrichial sweat glands may be obliterated.

T2670

902455-902543

Epistemic_statement

denotes

In some dogs, the condition is self-limiting, resolving in 1-3 months and rarely recurs.

T2671

902893-903051

Epistemic_statement

denotes

Cutaneous lesions associated with the cryoglobulinemia associated with multiple myelomas have been discussed elsewhere (see Other immune-mediated dermatoses).

T2672

903193-903303

Epistemic_statement

denotes

6-125A ) and has been reported to be associated with a concurrent pancreatic carcinoma or bile duct carcinoma.

T2673

903304-903403

Epistemic_statement

denotes

Crusting and brown-black waxy debris tends to be associated with a secondary Malassezia dermatitis.

T2674

903404-903461

Epistemic_statement

denotes

Pawpads may have concentric circular scales and fissures.

T2675

903527-903591

Epistemic_statement

denotes

Hair follicles are diffusely in telogen and appear miniaturized.

T2676

903592-903674

Epistemic_statement

denotes

Surrounding sebaceous glands are usually normal but may be atrophic in some cases.

T2677

903675-903835

Epistemic_statement

denotes

The epidermis is mildly hyperplastic and often lacks a stratum corneum, giving the regions of affected skin the characteristic "glistening" or moist appearance.

T2678

903836-903901

Epistemic_statement

denotes

The lack of the stratum corneum may be due to licking by the cat.

T2679

903902-903959

Epistemic_statement

denotes

In some areas, there may be parakeratotic hyperkeratosis.

T2680

904033-904076

Epistemic_statement

denotes

Pawpads may be softened and hyperkeratotic.

T2681

904388-904493

Epistemic_statement

denotes

Cats are usually aged and may have signs such as dyspnea and coughing referable to an intrathoracic mass.

T2682

904494-904570

Epistemic_statement

denotes

Cutaneous lesions may be well developed prior to onset of respiratory signs.

T2683

904571-904709

Epistemic_statement

denotes

The cutaneous lesions consist of dry exfoliative dermatitis with large scales over the head, neck, and pinnae that may become generalized.

T2684

904710-904940

Epistemic_statement

denotes

Brown, waxy material in middle-aged German Shepherd dogs and occasionally other breeds (Golden Retriever, Boxer, Belgian Shepherd, mixed breed) in association with renal cysts, renal cystadenocarcinomas, and/or uterine leiomyomas.

T2685

905016-905100

Epistemic_statement

denotes

The overlying skin may be normal, thickened, hyperpigmented, alopecic, or ulcerated.

T2686

905576-905788

Epistemic_statement

denotes

Severe generalized pruritus without primary gross or histologic cutaneous lesions or other identifiable cause for pruritus has been reported in the dog and horse in association with underlying malignant lymphoma.

T2687

905789-905860

Epistemic_statement

denotes

Self-trauma can lead to extensive excoriations and secondary infection.

T2688

905963-906105

Epistemic_statement

denotes

The mechanism of the development of pruritus is not understood but is speculated to be related to tumor-induced release of chemical mediators.

T2689

906106-906178

Epistemic_statement

denotes

Pruritus can only be relieved by successful treatment of the malignancy.

T2690

906368-906458

Epistemic_statement

denotes

Functional pheochromocytomas upon rare occasion can lead to cutaneous flushing in the dog.

T2691

906538-906702

Epistemic_statement

denotes

Occasionally, vesicular, pustular, or bullous dermatoses virtually identical to idiopathic autoimmune skin diseases may be associated with an underlying malignancy.

T2692

907030-907179

Epistemic_statement

denotes

A subepidermal bullous stomatitis microscopically identical to bullous pemphigoid has been reported in a horse in association with a hemangiosarcoma.

T2693

907458-907632

Epistemic_statement

denotes

Paraneoplastic pemphigus is a form of pemphigus that is sometimes associated with an underlying malignancy and has been previously discussed (see Immune-mediated dermatoses).

T2694

907753-907835

Epistemic_statement

denotes

Some lesions may have erythema, thickened skin, and marked crusting with alopecia.

T2695

908582-908804

Epistemic_statement

denotes

It has been speculated that the presence of a thymoma initiates abnormal immunologic responses responsible for the dermatitis, which at times can resemble erythema multiforme or graft-versus-host dermatitis histologically.

T2696

909019-909130

Epistemic_statement

denotes

The condition is sometimes associated with endocrine tumors of the pancreas (see Nutritional diseases of skin).

T2697

909131-909246

Epistemic_statement

denotes

Multiple collagenous hamartomas (nodular dermatofibrosis) of the distal limbs, head, and pinnae have been reported

T2698

909247-909404

Epistemic_statement

denotes

A resulting in well-demarcated, singular to multiple, raised, erythematous, alopecic, eroded to ulcerated to oozing plaques that can develop peracutely (Fig.

T2699

909535-909577

Epistemic_statement

denotes

Peripheral lymphadenopathy may be present.

T2700

909855-910003

Epistemic_statement

denotes

Inflammation in the dermis is perivascular to interstitial and sometimes diffuse, containing numerous eosinophils, and may extend into the subcutis.

T2701

910189-910332

Epistemic_statement

denotes

This lesion is the most variable in its clinical presentation and, of the 3 lesions in the EGC, is the most likely to be considered idiopathic.

T2702

910358-910424

Epistemic_statement

denotes

It can occur at any age; however, it is more common in young cats.

T2703

910425-910493

Epistemic_statement

denotes

Spontaneous regression can occur, especially in cats <1 year of age.

T2704

910494-910553

Epistemic_statement

denotes

A genetic predisposition has been documented in some cases.

T2705

910554-910682

Epistemic_statement

denotes

The lesions can be papular, nodular, or linear, and occur on the skin, pawpads, mucocutaneous junctions, and in the oral cavity.

T2706

910910-911021

Epistemic_statement

denotes

Some, especially oral lesions, may be ulcerated with multifocal pinpoint yellow to white foci over the surface.

T2707

911329-911416

Epistemic_statement

denotes

These foci may be surrounded by macrophages and multinucleated histiocytic giant cells.

T2708

912030-912147

Epistemic_statement

denotes

Eosinophils are one of the major sources of inflammatory mediators associated with type I hypersensitivity reactions.

T2709

912148-912274

Epistemic_statement

denotes

Eosinophils can phagocytize small antigens, and they can kill large parasites by releasing toxic substances via degranulation.

T2710

912685-912797

Epistemic_statement

denotes

Eosinophils also produce transforming growth factor-β that is associated with chronic inflammation and fibrosis.

T2711

913029-913248

Epistemic_statement

denotes

Eosinophilic inflammation in the horse and cat is a common tissue reaction, and it seems that the chemotactic stimuli that attract neutrophils in most species attract both eosinophils and neutrophils in these 2 species.

T2712

913459-913591

Epistemic_statement

denotes

These lesions can occur separately or together and, rather than a specific disease, are considered a mucocutaneous reaction pattern.

T2713

913743-914030

Epistemic_statement

denotes

In human patients with severe atopic dermatitis (AD), there is some evidence to suggest that although the disease is initiated by environmental allergens, some patients may form IgE antibodies directed against human proteins (self-antigens) generated through self-trauma from scratching.

T2714

914031-914156

Epistemic_statement

denotes

Felis domesticus allergen I (Feld I) could be an autoallergen responsible for chronic inflammatory reaction in cats with EGC.

T2715

914157-914279

Epistemic_statement

denotes

And in other cases, the lesions spontaneously resolve and do not recur, making allergy an unlikely trigger in those cases.

T2716

914280-914454

Epistemic_statement

denotes

Bacterial involvement may be a significant factor, especially with indolent ulcers and eosinophilic plaques, and in some cases, lesions resolve with antibiotic therapy alone.

T2717

914455-914572

Epistemic_statement

denotes

In some cases, the oral and lip lesions are thought to be due to embedded foreign material such as insects or plants.

T2718

914573-914718

Epistemic_statement

denotes

Because this condition has been reported in several groups of related cats, there is some evidence to suggest heritable eosinophil dysregulation.

T2719

915128-915277

Epistemic_statement

denotes

Nodular conditions of unknown etiology and pathogenesis include eosinophilic granuloma, axillary nodular necrosis, and unilateral papular dermatosis.

T2720

915278-915436

Epistemic_statement

denotes

Other eosinophilic nodular conditions with known etiologies, such as cutaneous habronemiasis, can look histologically similar (see Helminth diseases of skin).

T2721

915437-915724

Epistemic_statement

denotes

Cutaneous mast cell tumors in the horse can also be seen clinically as cutaneous nodular lesions, and, as histologically, they may contain significant numbers of eosinophils and areas of necrosis, care should be taken to differentiate this tumor from an inflammatory eosinophilic lesion.

T2722

915892-915985

Epistemic_statement

denotes

The condition is seen most often in the spring and summer, but can occur at any time of year.

T2723

915986-916038

Epistemic_statement

denotes

The etiology is unknown but probably multifactorial.

T2724

916285-916482

Epistemic_statement

denotes

The lesions occur as single or multiple, firm, raised, well-circumscribed, round papules or nodules measuring 0.5-10 cm in diameter, most commonly on focal eosinophilic panniculitis may be present.

T2725

916483-916528

Epistemic_statement

denotes

The epidermis may be acanthotic or ulcerated.

T2726

916614-916765

Epistemic_statement

denotes

Clinically, the condition is characterized by an ulcerated lesion on the upper lip adjacent to the philtrum, which can be unilateral or bilateral (Fig.

T2727

916815-916857

Epistemic_statement

denotes

Peripheral lymphadenopathy may be present.

T2728

916858-917214

Epistemic_statement

denotes

Histologically, the acute lesions are characterized by diffuse infiltrates of neutrophils with variable numbers of eosinophils, mast cells, and macrophages; however, the lesions are more often biopsied in the chronic phase when the inflammation is composed almost entirely of lymphocytes, plasma cells, macrophages, and neutrophils, together with fibrosis.

T2729

917384-917390

Epistemic_statement

denotes

Scott

T2730

917391-917547

Epistemic_statement

denotes

This rare disease typically occurs in young horses (mean 3-4 years of age) and is characterized by eosinophilic infiltration of many organs, including skin.

T2731

917548-917625

Epistemic_statement

denotes

The cause of multisystemic, eosinophilic, epitheliotropic disease is unknown.

T2732

917626-917713

Epistemic_statement

denotes

A genetic basis has been proposed; Standardbreds and Thoroughbreds are overrepresented.

T2733

917714-917848

Epistemic_statement

denotes

Recurrent episodes of type I hypersensitivity caused by dietary, inhaled, or parasitic antigens has been suggested in several reports.

T2734

917849-918170

Epistemic_statement

denotes

There is one report of this condition occurring concurrently with intestinal lymphoma, and several other unpublished cases that appear identical to the case described; the authors suggest that the clonal proliferation of T lymphocytes triggers proliferation of eosinophils by secretion of cytokines such as interleukin-5.

T2735

918171-918307

Epistemic_statement

denotes

This mechanism has also been proposed in humans who have concurrent abnormal T-lymphocyte proliferations and hypereosinophilic syndrome.

T2736

918658-918704

Epistemic_statement

denotes

Vesicles, bullae, and wheals are rarely noted.

T2737

918705-918770

Epistemic_statement

denotes

Pruritus is variable, and peripheral lymph nodes may be enlarged.

T2738

919457-919574

Epistemic_statement

denotes

An epitheliotropic infiltrate of eosinophils and lymphocytes is common, and apoptotic keratinocytes may be prominent.

T2739

919575-919660

Epistemic_statement

denotes

Eosinophilic folliculitis, furunculosis, and eosinophilic microabscesses may be seen.

T2740

920019-920101

Epistemic_statement

denotes

The granulomatous process is fairly linear in silicone-needle injection reactions.

T2741

920102-920169

Epistemic_statement

denotes

Free hair shafts within the lesion suggest previous close-clipping.

T2742

920170-920244

Epistemic_statement

denotes

Axillary nodular necrosis (girth galls) is a rare dermatosis of the horse.

T2743

920245-920284

Epistemic_statement

denotes

The cause and pathogenesis are unknown.

T2744

920285-920438

Epistemic_statement

denotes

The cutaneous and subcutaneous nodules are firm, round, well circumscribed, 1-10 cm in diameter, and can be single or multiple, usually not more than 10.

T2745

920439-920607

Epistemic_statement

denotes

They are usually unilateral and occur on the trunk behind the axilla, Lesions may also be seen caudal to the shoulder and on the proximal medial aspect of the forelimb.

T2746

921142-921176

Epistemic_statement

denotes

Necrotizing arteritis may be seen.

T2747

921344-921431

Epistemic_statement

denotes

It has been seen in many breeds, although Quarter Horses appear to be over-represented.

T2748

921432-921601

Epistemic_statement

denotes

The etiology is unknown; however, the seasonality of the lesions together with the eosinophilic nature of the histologic findings suggests ectoparasite hypersensitivity.

T2749

921602-921748

Epistemic_statement

denotes

It has further been suggested that the unilateral distribution may indicate direct contact hypersensitivity to an ectoparasite inhabiting bedding.

T2750

921948-922034

Epistemic_statement

denotes

There is neither pruritus nor pain; however, some lesions become crusted and alopecic.

T2751

922322-922490

Epistemic_statement

denotes

The cause is unknown; however, about 3 4 of the reported cases have been dogs treated for vomiting and diarrhea; thus drug association has been suspected in many cases.

T2752

922632-922684

Epistemic_statement

denotes

Eosinophilic intraepidermal pustules may be present.

T2753

922685-922700

Epistemic_statement

denotes

Mauldin EA, et

T2754

922701-922890

Epistemic_statement

denotes

Sterile neutrophilic dermatosis is a very rare condition, described in dogs, with marked similarities to the human disease known as acute febrile neutrophilic dermatosis (Sweet's syndrome).

T2755

923093-923203

Epistemic_statement

denotes

The pathogenesis is unknown; however, it is believed to be an antigen-induced T-cell-mediated immune reaction.

T2756

923204-923296

Epistemic_statement

denotes

Possible triggers include drugs, respiratory and gastrointestinal infections, and neoplasia.

T2757

923297-923345

Epistemic_statement

denotes

Three cases have been associated with carprofen.

T2758

923526-923661

Epistemic_statement

denotes

Subcorneal pustular dermatosis is a very rare, sterile, superficial, pustular condition of dogs with an unknown cause and pathogenesis.

T2759

923948-924020

Epistemic_statement

denotes

Lesions may spread peripherally into annular and serpiginous formations.

T2760

924021-924061

Epistemic_statement

denotes

Pruritus is variable and may be extreme.

T2761

924062-924090

Epistemic_statement

denotes

Pawpads are rarely affected.

T2762

924336-924492

Epistemic_statement

denotes

The etiology of this condition has not been fully characterized, but a hypersensitivity reaction to insect stings and arthropod bites is strongly suspected.

T2763

924792-924832

Epistemic_statement

denotes

Pruritus is variable but can be intense.

T2764

924867-925069

Epistemic_statement

denotes

In horses, sterile eosinophilic folliculitis and furunculosis can be seen in horses with atopic dermatitis, insect-bite hypersensitivity, food allergy, unilateral papular dermatosis, and onchocerciasis.

T2765

925070-925312

Epistemic_statement

denotes

Lesions are characterized by tufted papules that become alopecic and crusted in a generally symmetrical and multifocal distribution anywhere on the body; however, the neck, shoulders, chest, and dorsolateral thorax are most commonly affected.

T2766

925599-925654

Epistemic_statement

denotes

The condition in nonseasonal, and the cause is unknown.

T2767

925655-925941

Epistemic_statement

denotes

In cats, sterile eosinophilic folliculitis and furunculosis may be seen as a bystander lesion in any allergic dermatitis; however, it is more commonly seen in mosquito-bite hypersensitivity and feline herpesvirus dermatitis, both of which are most commonly located on the face and head.

T2768

926286-926329

Epistemic_statement

denotes

Dermal hemorrhage may be prominent in dogs.

T2769

926330-926368

Epistemic_statement

denotes

Collagen flame figures may be present.

T2770

926457-926500

Epistemic_statement

denotes

There may also be erosions and ulcerations.

T2771

926501-926674

Epistemic_statement

denotes

Canine sterile eosinophilic pinnal folliculitis is an uncommon, nonseasonal, bilaterally symmetrical dermatosis with variable pruritus and an unknown cause and pathogenesis.

T2772

926830-926993

Epistemic_statement

denotes

This is a rare idiopathic dermatosis of dogs characterized by peripheral eosinophilia, sterile tissue eosinophilia, and responsiveness to systemic glucocorticoids.

T2773

927321-927414

Epistemic_statement

denotes

There may be various degrees of flame figures and eosinophilic folliculitis and furunculosis.

T2774

927415-927508

Epistemic_statement

denotes

Grossly, the lesions consist of progressive alopecia and scaling that may become generalized.

T2775

927509-927599

Epistemic_statement

denotes

A disease resembling follicular mucinosis in humans has been described in the cat and dog.

T2776

928456-928554

Epistemic_statement

denotes

In humans, follicular mucinosis can resolve spontaneously or become a chronic relapsing condition.

T2777

928555-928618

Epistemic_statement

denotes

Many cases are thought to progress to epitheliotropic lymphoma.

T2778

928619-928734

Epistemic_statement

denotes

It should be noted that epidermal and epithelial mucinosis can be seen in various allergic dermatitides of the cat.

T2779

930082-930287

Epistemic_statement

denotes

This condition is very rare and is characterized by dermal mucin deposits on the head and legs, increased numbers of fibroblasts, variable fibrosis, absence of thyroid disease, and a monoclonal gammopathy.

T2780

930534-930637

Epistemic_statement

denotes

As the rings expand, they coalesce to produce mosaic patterns and may extend to the sides and perineum.

T2781

930778-930871

Epistemic_statement

denotes

There may be epidermal spongiosis with intraepidermal eosinophilic and neutrophilic pustules.

T2782

930872-930951

Epistemic_statement

denotes

Superficial epidermal necrosis may extend into the ostia of the hair follicles.

T2783

931609-931669

Epistemic_statement

denotes

Lesions may resolve during lactation but recur with weaning.

T2784

932060-932165

Epistemic_statement

denotes

The latter pattern suggests that this condition may be a form of vesicular cutaneous lupus erythematosus.

T2785

932166-932367

Epistemic_statement

denotes

Recurrent dermatosis of sows is a rare idiopathic condition characterized by nonpruritic, erythematous macules and patches that enlarge and become scaly, especially on the trunk and only in white skin.

T2786

932368-932551

Epistemic_statement

denotes

Hairs within the lesion become Localized scleroderma (morphea) and cicatricial alopecia Localized scleroderma (morphea) is a rare disease described in humans, dogs, cats, and a horse.

T2787

932552-932719

Epistemic_statement

denotes

The cause is unknown; but in humans, vascular injury, abnormal collagen metabolism, and an immune-mediated pathogenesis, such as drug reaction, have all been proposed.

T2788

932834-932861

Epistemic_statement

denotes

Hypopigmentation may occur.

T2789

933223-933339

Epistemic_statement

denotes

Cicatricial alopecia is grossly and microscopically very similar; however, in this condition, lesions are permanent.

T2790

933637-933681

Epistemic_statement

denotes

Scattered orphaned sweat glands may be seen.

T2791

933682-933839

Epistemic_statement

denotes

Generalized scleroderma is a rare multisystemic disorder that results in progressive fibrosis of the skin, lungs, gastrointestinal tract, kidneys, and heart.

T2792

933840-933884

Epistemic_statement

denotes

It has been described in humans and a horse.

T2793

933885-933898

Epistemic_statement

denotes

Frank LA, et

T2794

933899-933980

Epistemic_statement

denotes

This is a rare condition described in pygmy goats and alpine goats most commonly.

T2795

934035-934148

Epistemic_statement

denotes

Lesions are nonpruritic and begin on the face and pinnae and may also affect the neck, ventrum, and distal limbs.

T2796

934543-934769

Epistemic_statement

denotes

Because the clinical signs and gross lesions bear little relationship to those of the human disease for which it was originally named, the new designation, porcine juvenile pustular psoriasiform dermatitis, has been suggested.

T2797

934822-934845

Epistemic_statement

denotes

The cause is not known.

T2798

934846-934939

Epistemic_statement

denotes

A hereditary predisposition has been suggested but not proved, particularly in Landrace pigs.

T2799

935001-935054

Epistemic_statement

denotes

Entire litters or just a few piglets may be affected.

T2800

935055-935170

Epistemic_statement

denotes

The disease begins with symmetrical, nonpruritic, scaly, erythematous papules on the skin of the abdomen and inner

T2801

935171-935253

Epistemic_statement

denotes

Perforating dermatitis is a rare, distinctive reaction pattern in cats and humans.

T2802

935431-935485

Epistemic_statement

denotes

The lesions may be arranged in a linear configuration.

T2803

935857-935892

Epistemic_statement

denotes

There may be subepidermal fibrosis.

T2804

935946-936050

Epistemic_statement

denotes

The cause is unknown, although some cases may occur secondary to self-trauma from allergic skin disease.

T2805

936051-936173

Epistemic_statement

denotes

It has been proposed that this condition is the result of abnormal wound healing possibly caused by abnormal collagenesis.

T2806

936221-936366

Epistemic_statement

denotes

Masson trichrome staining of affected collagen fibers demonstrates segmental red cores; however, this finding is not specific for this condition.

T2807

936587-936594

Epistemic_statement

denotes

Kimura

T2808

936595-936702

Epistemic_statement

denotes

Abnormal sebaceous gland differentiation (sebaceous gland dysplasia) is a rare dermatosis in cats and dogs.

T2809

936846-936958

Epistemic_statement

denotes

In kittens, it is characterized by hypotrichosis with scaling that is apparent as early as 4 weeks of age (eFig.

T2810

937134-937258

Epistemic_statement

denotes

The cause is unknown; however, the juvenile onset suggests a genetic defect leading to abnormal sebaceous gland development.

T2811

937799-937906

Epistemic_statement

denotes

Degenerative, dysplastic, and horses and some cats, multinucleated histiocytic giant cells may be numerous.

T2812

937948-938097

Epistemic_statement

denotes

In dogs, Collies, Boxers, Great Danes, Weimaraners, English Bulldogs, Doberman Pinschers, Dachshunds, and Golden Retrievers appear to be predisposed.

T2813

938098-938266

Epistemic_statement

denotes

In most dogs, the lesions are multiple, nonpainful, nonpruritic, and can occur anywhere on the body; however, the face and distal extremities are the most common sites.

T2814

938267-938361

Epistemic_statement

denotes

Lymphadenopathy occurs in some cases, and rarely, there can be pyogranulomatous lymphadenitis.

T2815

938362-938418

Epistemic_statement

denotes

The condition may spontaneously resolve or wax and wane.

T2816

938715-938796

Epistemic_statement

denotes

Lesions are violaceus or orangeyellow and may become red to purple when palpated.

T2817

938797-938930

Epistemic_statement

denotes

Xanthomas (xanthogranulomas) are single to multiple nodular lesions occurring rarely in the cat and very rarely in the dog and horse.

T2818

940246-940457

Epistemic_statement

denotes

Equine sarcoidosis (idiopathic generalized or systemic granulomatous disease) is rare and may be seen as a generalized or localized exfoliative dermatitis and/or as granulomatous inflammation in multiple organs.

T2819

940458-940589

Epistemic_statement

denotes

The cause is unknown; however, an immune-mediated pathogenesis, Mycobacterium spp., and hairy vetch toxicosis have been implicated.

T2820

940705-940760

Epistemic_statement

denotes

Peripheral lymphadenopathy may occur in the former two.

T2821

941067-941268

Epistemic_statement

denotes

The generalized form shows nonpruritic cutaneous signs and or (sub)cutaneous nodules all over the body with one or more of the following signs: low-grade fever, exercise intolerance, pain when touched,

T2822

941269-941368

Epistemic_statement

denotes

The sterile granuloma/pyogranuloma syndrome (SPGS) is uncommon in dogs and rare in cats and horses.

T2823

941369-941612

Epistemic_statement

denotes

The cause is unknown; however, negative tissue cultures, negative special stains for microbial agents, absence of foreign material with polarization, and good response to immunomodulatory therapy have suggested an immune-mediated pathogenesis.

T2824

941613-941768

Epistemic_statement

denotes

It has been hypothesized by some that SPGS may be caused by an immune response against persistent endogenous or exogenous antigens, such as Leishmania spp.

T2825

942016-942070

Epistemic_statement

denotes

Lesions may become ulcerated and secondarily infected.

T2826

942301-942399

Epistemic_statement

denotes

Older lesions may become diffuse, obliterating adnexal structures and extending into the subcutis.

T2827

942568-942599

Epistemic_statement

denotes

The condition can be recurrent.

T2828

942713-942840

Epistemic_statement

denotes

Lesions in the horse are most often found on the neck, thorax, abdomen, and proximal limbs, and may elicit pain upon palpation.

T2829

942841-942876

Epistemic_statement

denotes

Shetland ponies may be predisposed.

T2830

942981-943060

Epistemic_statement

denotes

Lesions in cattle have been described over the neck, trunk, and proximal limbs.

T2831

943257-943310

Epistemic_statement

denotes

Discrete granulomas and pyogranulomas may be present.

T2832

943311-943380

Epistemic_statement

denotes

Adipocytes may appear necrotic or infiltrated with foamy macrophages.

T2833

943529-943740

Epistemic_statement

denotes

Sterile panniculitis may be indistinguishable histologically from the panniculitides of infectious cause, and thus tissue culture and special stains for microbial agents are necessary for a definitive diagnosis.

T2834

943741-943933

Epistemic_statement

denotes

The presence of saponification of fat and fat necrosis, along with diffuse infiltrates of pyogranulomatous inflammation, is associated with pancreatic disease and vitamin E deficiency in cats.

T2835

943934-943985

Epistemic_statement

denotes

The latter is also associated with ceroid deposits.

T2836

943986-944042

Epistemic_statement

denotes

Septal panniculitis is often associated with vasculitis.

T2837

944580-944711

Epistemic_statement

denotes

Affected animals with single lesions may be asymptomatic; animals with multiple lesions often have pyrexia, lethargy, and anorexia.

T2838

945058-945215

Epistemic_statement

denotes

Laminitis is a cutaneous manifestation of a systemic problem, and thus there are many risk factors and potential causes that can be categorized into 3 forms.

T2839

945708-945906

Epistemic_statement

denotes

• Endocrinopathic laminitis/laminopathy is the second form and includes horses with insulin resistance, obesity, pituitary pars intermedia dysfunction, and possibly corticosteroid-induced laminitis.

T2840

945907-946073

Epistemic_statement

denotes

This form is characterized by little if any inflammation and stretching of the secondary epidermal lamellae as opposed to early separation from the basement membrane.

T2841

946074-946184

Epistemic_statement

denotes

This will still lead to eventual basement membrane separation at the tips of the secondary epidermal lamellae.

T2842

946185-946482

Epistemic_statement

denotes

• The third form, contralateral limb laminitis/laminopathy, is thought to be initiated by poor blood flow and ischemia and likely involves subsequent enzyme activation and degradation of the lamellar basement membrane in conjunction with the effects of tension and stretch on the lamellar tissues.

T2843

946546-946829

Epistemic_statement

denotes

Laminitis is a syndrome with many contributing factors, and although there may be different pathways, the common lesion in all forms of the disease is dermal-epidermal separation at the interface of the lamellar basal epithelial cells and the underlying basement membrane and dermis.

T2844

947324-947505

Epistemic_statement

denotes

Loss of the basement membrane leads to separation of the dermal and epidermal laminae of the hoof wall and is crucial in loss of structural integrity of the P3/hoof wall attachment.

T2845

947839-947982

Epistemic_statement

denotes

Acute laminitis is seen as sudden lameness and severe pain affecting most commonly the forefeet but may affect all feet, or just the hind feet.

T2846

948328-948413

Epistemic_statement

denotes

There is no hoof deformity, although the skin above the coronary band may be swollen.

T2847

948414-948512

Epistemic_statement

denotes

Horses with diffuse swelling and depression along the coronary band are often found to have acute

T2848

948513-948633

Epistemic_statement

denotes

The hoof wall is a complex structure composed of an epidermis and dermis that attaches to the underlying distal phalanx.

T2849

949397-949496

Epistemic_statement

denotes

Traditionally, it has been thought that laminitis is caused by one common pathophysiologic pathway.

T2850

949497-949646

Epistemic_statement

denotes

Currently, it is Also included in this section are varieties of tumor-like or keratin-filled cystic lesions that can be confused with true neoplasms.

T2851

950285-950445

Epistemic_statement

denotes

In long-standing lesions, the epithelial wall may become very thin, and rupture may release entrapped keratin to stimulate pyogranulomatous dermal inflammation.

T2852

950594-950714

Epistemic_statement

denotes

In addition, the dermis may be congested, edematous, and have mild hemorrhage and mild infiltrates of mononuclear cells.

T2853

950715-950785

Epistemic_statement

denotes

In time, coagulative necrosis of the secondary laminae may be evident.

T2854

951437-951530

Epistemic_statement

denotes

In severely affected animals, the third phalanx may penetrate the sole, which becomes convex.

T2855

951700-951773

Epistemic_statement

denotes

The corium at the coronary band and sole may be edematous or hemorrhagic.

T2856

952116-952202

Epistemic_statement

denotes

In cattle, carbohydrate overload is also an important predisposing cause of laminitis.

T2857

952814-952950

Epistemic_statement

denotes

The regenerating secondary laminae may not regain their orderly arrangement and instead form irregular and anastomosing epidermal cords.

T2858

953034-953081

Epistemic_statement

denotes

The reason for the hyperkeratosis is not known.

T2859

953082-953180

Epistemic_statement

denotes

Both physical and physiologic influences on keratogenesis are likely altered in chronic laminitis.

T2860

953839-953911

Epistemic_statement

denotes

infection have been suggested, although not proven, causes of keratomas.

T2861

954184-954289

Epistemic_statement

denotes

Some dermoid cysts may extend deep into the tissue and be connected to the dura mater of the spinal cord.

T2862

955069-955204

Epistemic_statement

denotes

They may be single or multiple, smooth, most often unilocular, spherical dermal papules or nodules seldom larger than 1 cm in diameter.

T2863

955205-955244

Epistemic_statement

denotes

The keratin may appear as loose flakes.

T2864

955245-955437

Epistemic_statement

denotes

Infundibular cysts may arise from dilation of the infundibulum of occluded hair follicles, and indeed, occasionally one can detect superficial dermal scarring that may support this hypothesis.

T2865

955438-955502

Epistemic_statement

denotes

As well, such cysts may contain fragments of mature hair shafts.

T2866

955611-955746

Epistemic_statement

denotes

Some cysts are thought to arise from traumatic, developmental, or surgical implantation of epidermal fragments into dermis or subcutis.

T2867

955823-956000

Epistemic_statement

denotes

One dog was reported to have >100 infundibular cysts in the perianal area, possibly resulting from chronic external trauma to the perianal area as a response to anal sacculitis.

T2868

956001-956134

Epistemic_statement

denotes

Occasionally, an infundibular cyst can be found within the bone of the third phalanx of the dog (subungual epidermal inclusion cyst).

T2869

956135-956232

Epistemic_statement

denotes

Isthmus cyst (trichilemmal cyst) is lined by keratinizing epithelium that lacks a granular layer.

T2870

956986-957064

Epistemic_statement

denotes

The presence of 2 or 3 types of keratin may help support this diagnosis ( Fig.

T2871

957074-957203

Epistemic_statement

denotes

Dilated pore of Winer is a flask-shaped epidermal cyst on the head or neck of middle-aged or old cats and rarely dogs and horses.

T2872

957444-957508

Epistemic_statement

denotes

Keratin may protrude through the pore, forming a cutaneous horn.

T2873

957640-957749

Epistemic_statement

denotes

They are thought to originate from the epidermal horn-producing cells of either the coronary or solar corium.

T2874

957750-957819

Epistemic_statement

denotes

They are rare but do occur in both simple- and cloven-hoofed animals.

T2875

957849-958002

Epistemic_statement

denotes

The cysts are usually solitary, 1-5 cm in diameter, and often exert pressure on P3, leaving an area of bone resorption that can be seen radiographically.

T2876

958003-958060

Epistemic_statement

denotes

There are rare reports of horses with multiple keratomas.

T2877

958152-958311

Epistemic_statement

denotes

Histologically, the cyst is lined by squamous epithelium of the primary epidermal lamellae and filled with laminated keratin that in some cases may mineralize.

T2878

958469-958564

Epistemic_statement

denotes

• Sweat gland hamartomas are rare in domestic animals but have been described in cats and dogs.

T2879

958708-958762

Epistemic_statement

denotes

• Trichofolliculoma is also thought to be a hamartoma.

T2880

958763-958803

Epistemic_statement

denotes

It is uncommon in dogs and rare in cats.

T2881

959432-959585

Epistemic_statement

denotes

These lesions are most often seen on the eyelids, face, conjunctiva, or pawpads of older dogs and occasionally cats, and they may be traumatic in origin.

T2882

959673-959795

Epistemic_statement

denotes

Congenital papillomas, which may actually represent epidermal hamartomas, have been reported in newborn foals and fetuses.

T2883

959875-960061

Epistemic_statement

denotes

Cutaneous horns are rare exophytic cylindrical formations of compact keratin a few millimeters in diameter and 1-2 cm in length, formed by an underlying markedly hyperplastic epithelium.

T2884

960106-960294

Epistemic_statement

denotes

Cutaneous horns may arise from viral papillomas, actinic keratosis, squamous cell carcinoma (bowenoid in situ or invasive), infundibular keratinizing acanthomas, or dilated pores of Winer.

T2885

960295-960391

Epistemic_statement

denotes

Cutaneous horns of the pawpad of cats have been associated with feline leukemia virus infection.

T2886

960392-960531

Epistemic_statement

denotes

Warty dyskeratoma is a rare a cystic cup-shaped dermal mass lined by stratified squamous epithelium resembling the follicular infundibulum.

T2887

960898-961094

Epistemic_statement

denotes

Specimens with only hair follicle differentiation may be confused with unilocular trichoepitheliomas, but the dermoid cyst has gradual keratinization rather than abrupt trichilemmal cornification.

T2888

961095-961256

Epistemic_statement

denotes

Epitrichial (apocrine) cysts may be single or multiple and are filled with clear secretions and lined by a single layer of cuboidal to columnar epithelial cells.

T2889

961346-961434

Epistemic_statement

denotes

This is an uncommon lesion that occurs in middle-aged to older dogs for unknown reasons.

T2890

961435-961475

Epistemic_statement

denotes

Sebaceous duct cysts are extremely rare.

T2891

961476-961536

Epistemic_statement

denotes

They are usually solitary and may occur in Meibomian glands.

T2892

962104-962323

Epistemic_statement

denotes

• Epidermal hamartomas (pigmented epidermal nevus, linear epidermal hamartoma, verrucous epidermal nevus) grossly appear as focal hyperkeratotic plaques or papules forming one or more linear arrays on the trunk or legs.

T2893

962469-962533

Epistemic_statement

denotes

The stratum granulosum may have enlarged keratohyaline granules.

T2894

962534-962626

Epistemic_statement

denotes

In the dog, an association with papilloma virus infection has been documented in some cases.

T2895

962627-962722

Epistemic_statement

denotes

Linear epidermal hamartomas are thought to be a genetically inherited lesion in Belgian horses.

T2896

963076-963154

Epistemic_statement

denotes

Associated glands surround the follicles and sebaceous glands may be enlarged.

T2897

963435-963728

Epistemic_statement

denotes

• Fibroadnexal hamartoma (adnexal nevus, focal adnexal dysplasia, folliculosebaceous hamartoma) is a common lesion in dogs and consists of aggregates of markedly distorted and variably inflamed folliculosebaceous units surrounded by dense collagen and lacking a connection to the skin surface.

T2898

963930-964026

Epistemic_statement

denotes

Some pathologists believe this type of lesion is a result of trauma and is not a true hamartoma.

T2899

964130-964235

Epistemic_statement

denotes

Histologi-microscopy and viral antigen detectable by immunohistochemistry, but these may not be numerous.

T2900

964998-965125

Epistemic_statement

denotes

Bovine papillomatosis may be a herd problem in that the virus is easily transmitted by animal-to-animal contact and by fomites.

T2901

965126-965245

Epistemic_statement

denotes

Depending on the anatomic site and papillomavirus type, both morphologic and biological features of lesions may differ.

T2902

965307-965319

Epistemic_statement

denotes

BPV-2 causes

T2903

965320-965433

Epistemic_statement

denotes

Cutaneous papillomas are benign proliferative epithelial neoplasms that have a complex etiology and pathogenesis.

T2904

966205-966414

Epistemic_statement

denotes

However, for viral replication to occur, infected cells must become terminally differentiated, and therefore PVs attempt to increase both proliferation of basal cells and terminal keratinocyte differentiation.

T2905

966573-966665

Epistemic_statement

denotes

The beta-PV genus contains cutaneous PVs that are usually associated with immunosuppression.

T2906

966666-966797

Epistemic_statement

denotes

The delta-PV type is important in nonhuman mammals because it is associated with benign fibropapillomas in both ungulates and cats.

T2907

966798-966912

Epistemic_statement

denotes

Although most papillomaviruses are species specific, delta-PVs have the unique ability to infect multiple species.

T2908

966998-967324

Epistemic_statement

denotes

Papillomaviruses induce and/ or are associated with several types of cutaneous lesions, including squamous papilloma, inverted papilloma, feline viral plaques, canine pigmented viral plaques, bowenoid in situ carcinoma (BISC), invasive squamous cell carcinoma (ISCC), and fibropapillomas, including equine and feline sarcoids.

T2909

967325-967455

Epistemic_statement

denotes

Viral papillomas may regress as a result of cell-mediated immune attack, may persist, or may progress to squamous cell carcinomas.

T2910

967456-967617

Epistemic_statement

denotes

Although some viral and host factors are known to influence the behavior of viral-induced papillomas and fibropapillomas, many other factors are not yet defined.

T2911

967831-967882

Epistemic_statement

denotes

Lesions can be anatomically extensive and multiple.

T2912

968297-968457

Epistemic_statement

denotes

Degenerating keratinocytes may have condensed eosinophilic cytoplasmic inclusions that represent aggregates of keratin, a result of the viral cytopathic effect.

T2913

968458-968566

Epistemic_statement

denotes

These inclusions should not be confused with the cytoplasmic inclusions associated with poxvirus infections.

T2914

968662-968937

Epistemic_statement

denotes

Cells of the stratum spinosum and granulosum may have vesicular nuclei with intranuclear pale basophilic viral inclusions that contain virus particles visible with electron A B keratomatous papilloma has been described in association with PV in an 8-month-old Simmental calf.

T2915

969185-969323

Epistemic_statement

denotes

It is believed to be critical in driving cell transformation, especially by activating platelet-derived growth factor receptor β (PDGFRβ).

T2916

969593-969680

Epistemic_statement

denotes

TLR-4 downregulation is expected to contribute to immune evasion and viral persistence.

T2917

969681-969879

Epistemic_statement

denotes

In conjunction with several BPVs (BPV-1, BPV-2, and BPV-4), the ingestion of bracken fern (Pteridium aquilinum) has been associated with various epithelial and mesenchymal urinary bladder neoplasms.

T2918

970089-970259

Epistemic_statement

denotes

Congenital papillomatosis was described in a Holstein heifer, and although BPV-3 was suspected, a viral etiology was not proved, and thus these lesions may be hamartomas.

T2919

971046-971137

Epistemic_statement

denotes

These rarely spontaneously regress and can occur anywhere on the body, including the teats.

T2920

971499-971606

Epistemic_statement

denotes

Some BPVs are associated with neoplastic transformation in the skin, alimentary tract, and urinary bladder.

T2921

971787-971932

Epistemic_statement

denotes

The most important papillomavirus-induced lesion in the horse is the sarcoid, known to be associated with BPV-1, BPV-2, and most recently BPV-13.

T2922

972127-972287

Epistemic_statement

denotes

A combination of factors appears to be involved in development of the tumors, including exposure to a viral agent, cutaneous trauma, and a genetic predilection.

T2923

972569-972772

Epistemic_statement

denotes

BPV DNA has been demonstrated in normal skin of healthy horses and horses with inflammatory conditions, suggesting that there are more factors involved in sarcoid development than simply viral infection.

T2924

973041-973311

Epistemic_statement

denotes

In Thoroughbreds and Warmbloods, the increased risk has been associated with major histocompatibility complex (MHC)-1 A3 and W13 alleles, whereas, in Standardbreds and Lipizzaners, a decreased risk is associated with decreased W13 allele and a lack of W13, respectively.

T2925

973396-973427

Epistemic_statement

denotes

They may be single or multiple.

T2926

973428-973515

Epistemic_statement

denotes

Young horses 1-7 years of age are at increased risk, with rare reports in older horses.

T2927

973659-973752

Epistemic_statement

denotes

Many horses have multiple tumors, and all types of sarcoids can be present in the same horse.

T2928

974213-974284

Epistemic_statement

denotes

The overlying skin may be normal but can become alopecic and ulcerated.

T2929

974340-974595

Epistemic_statement

denotes

The fibroblastic sarcoid is more variable in appearance and may range from a well-circumscribed firm nodule with intact surface to large masses, >25 cm in diameter, with an ulcerated surface prone to hemorrhage and resembling exuberant granulation tissue.

T2930

974818-974935

Epistemic_statement

denotes

The occult and verrucous and, to a lesser extent, the nodular sarcoid can remain static for years if not traumatized.

T2931

974936-975053

Epistemic_statement

denotes

Any type of sarcoid lesion can develop into an aggressive fibroblastic or malignant/ malevolent tumor if traumatized.

T2932

975054-975084

Epistemic_statement

denotes

Spontaneous remission is rare.

T2933

975605-975721

Epistemic_statement

denotes

Equine genital papillomas caused by EcPV-2 usually occur on older horses and are not known to spontaneously resolve.

T2934

975722-975897

Epistemic_statement

denotes

This virus has been associated with malignant transformation of penile and vulvar lesions to squamous cell carcinoma (SCC) in situ and invasive squamous cell carcinoma (ISCC).

T2935

975898-976028

Epistemic_statement

denotes

Equine ear papillomas (aural plaques) occur in horses of all ages, rarely spontaneously resolve, and are associated with EcPV 3-6.

T2936

976150-976260

Epistemic_statement

denotes

Fully developed lesions are usually bilaterally symmetrical and appear as 1-3 cm white hyperkeratotic plaques.

T2937

976261-976313

Epistemic_statement

denotes

Blackfly bites may be important in the transmission.

T2938

976314-976457

Epistemic_statement

denotes

Aural plaques are similar histologically to exophytic papillomas; however, the epidermis is less papillated, and hypomelanosis may be striking.

T2939

976458-976500

Epistemic_statement

denotes

EcPV-4 has also been isolated from vulvar

T2940

976501-976592

Epistemic_statement

denotes

may be minimal or absent in some tumors, especially nodular and early occult sarcoids (Fig.

T2941

976853-976918

Epistemic_statement

denotes

The fibroblasts have plump nuclei, and nucleoli may be prominent.

T2942

977265-977367

Epistemic_statement

denotes

Tumor margins are typically indistinct, and adequacy of excision is frequently difficult to determine.

T2943

977368-977549

Epistemic_statement

denotes

When the tumor is ulcerated, it may not be possible to differentiate a sarcoid from granulation tissue, fibroma, well-differentiated fibrosarcoma, and peripheral nerve sheath tumor.

T2944

977550-977657

Epistemic_statement

denotes

Immunohistochemical staining for S-100 protein may be useful in confirming a peripheral nerve sheath tumor.

T2945

977658-977742

Epistemic_statement

denotes

Additional biopsies to include intact epidermis may be required to make a diagnosis.

T2946

977743-977943

Epistemic_statement

denotes

BPV infection of equine fibroblasts appears to be mainly nonproductive with respect to producing complete viruses, and therefore there is no histologic or immunohistochemical evidence of PV infection.

T2947

978058-978163

Epistemic_statement

denotes

Ovis aries papillomavirus 1 and 2 (OaPV-1, OaPV-2) are delta-PVs and are associated with fibropapillomas.

T2948

978164-978215

Epistemic_statement

denotes

OaPV-3 (dyolambda-PV) has been associated with SCC.

T2949

978420-978469

Epistemic_statement

denotes

Similar lesions may occur on the scrotum of rams.

T2950

978818-978933

Epistemic_statement

denotes

In the second form, papillomas occur on the udder and teats of white goats especially; cutaneous horns may develop.

T2951

978934-979016

Epistemic_statement

denotes

There is no spontaneous regression, and malignant transformation to SCC can occur.

T2952

979085-979160

Epistemic_statement

denotes

PV DNA sequenes have only been detected in some goats with mammary lesions.

T2953

979472-979576

Epistemic_statement

denotes

Canine oral papillomatosis has been associated with CPV-1 (Canine oral papillomavirus, COPV) and CPV-13.

T2954

979904-979974

Epistemic_statement

denotes

Oral papillomatosis is occasionally associated with immunosuppression.

T2955

979975-980162

Epistemic_statement

denotes

It has been described in Beagles with IgA deficiency, in dogs undergoing immunosuppressive therapy with cyclosporine, and in a Chinese Shar-Pei in association with glucocorticoid therapy.

T2956

980261-980310

Epistemic_statement

denotes

They are associated with CPV-1, CPV-2, and CPV-7.

T2957

980311-980391

Epistemic_statement

denotes

They may be single to multiple, occurring mainly on the head, eyelids, and paws.

T2958

980591-980728

Epistemic_statement

denotes

Cutaneous inverted papillomas are usually seen in young adult dogs <3 years of age and have been associated with CPV-1, CPV-2, and CPV-6.

T2959

980859-980986

Epistemic_statement

denotes

They occur most commonly on the ventral abdomen and groin, can occur on limbs and digits and most do not regress spontaneously.

T2960

980987-981094

Epistemic_statement

denotes

Histologically, these lesions are cup shaped with a central core of keratin that may be parakeratotic (Fig.

T2961

981198-981254

Epistemic_statement

denotes

The cells may exhibit koilocytes or blue-gray cytoplasm.

T2962

981255-981327

Epistemic_statement

denotes

Large keratohyaline granules and intranuclear inclusions may be present.

T2963

981328-981419

Epistemic_statement

denotes

Malignant transformation has been associated with CPV-2 infection in immunosuppressed dogs.

T2964

981420-981553

Epistemic_statement

denotes

Canine pigmented plaques may be heritable because they are most commonly reported in certain breeds: Miniature only 2 cases reported.

T2965

981695-981762

Epistemic_statement

denotes

Interestingly, human papillomavirus 9 was isolated from the latter.

T2966

981763-981897

Epistemic_statement

denotes

Feline viral plaques are uncommon and occur as multiple scaly, flat, variably pigmented lesions that can develop anywhere on the body.

T2967

981898-982139

Epistemic_statement

denotes

Felis catus papillomavirus 1 (FcaPV-1), also called Felis domesticus PV-1 (FdPV-1) , a lambda-PV, and FcaPV-2, a dyotheta-PV, have been isolated from these lesions; however, FcaPV-2 has also been isolated from many cats with no skin lesions.

T2968

982140-982231

Epistemic_statement

denotes

Viral plaques may spontaneously resolve; however, some have been known to progress to BISC.

T2969

982232-982396

Epistemic_statement

denotes

In fact, FcaPV-2 DNA has been detected in many feline BISC lesions and up to 50% of ISCC lesions and is thought to play a role in the pathogenesis of these lesions.

T2970

982397-982516

Epistemic_statement

denotes

Feline viral plaques have been associated with immunosuppression in some cats but have also been noted in healthy cats.

T2971

982706-982775

Epistemic_statement

denotes

Small numbers of koilocytes may be present in the stratum granulosum.

T2972

982776-982945

Epistemic_statement

denotes

Feline BISC (a multicentric squamous cell carcinoma in situ) usually appears as multiple crusting, hyperpigmented, roughly circular plaques in middle-aged to older cats.

T2973

982946-982973

Epistemic_statement

denotes

Solitary lesions may occur.

T2974

982974-983019

Epistemic_statement

denotes

The face, neck, and limbs may be predisposed.

T2975

983020-983043

Epistemic_statement

denotes

It is uncommon to rare.

T2976

983044-983091

Epistemic_statement

denotes

Lesions may be more severe Schnauzers and Pugs.

T2977

983613-983664

Epistemic_statement

denotes

Koilocytes and viral inclusions are rare to absent.

T2978

983665-983794

Epistemic_statement

denotes

The potential for transformation to bowenoid in situ carcinoma (BISC), and ISCC has been reported in lesions infected with CPV-3.

T2979

983795-983886

Epistemic_statement

denotes

Canine pigmented papules have been rarely associated with long-term glucocorticoid therapy.

T2980

984083-984151

Epistemic_statement

denotes

These lesions may resolve after cessation of glucocorticoid therapy.

T2981

984152-984228

Epistemic_statement

denotes

Like other PVs, some CPVs have been associated with ISCC and some with BISC.

T2982

984325-984452

Epistemic_statement

denotes

One dog had multiple oral and cutaneous papillomas, oral SCC associated with CPV-1, and was thought to have T-cell dysfunction.

T2983

984553-984710

Epistemic_statement

denotes

Papillomavirus infection has been associated with cutaneous papillomas, feline viral plaques, feline sarcoid (feline fibropapilloma), BISC, and ISCC in cats.

T2984

984711-984812

Epistemic_statement

denotes

PV-induced exophytic cutaneous papillomas are rare in domestic cats, with A that recurred and spread.

T2985

984940-985047

Epistemic_statement

denotes

Camelus dromedarius papillomavirus 1 (delta-PV) has been associated with fibropapillomas in Arabian camels.

T2986

985524-985662

Epistemic_statement

denotes

Rarely, intrafollicular Demodex cati can be found in these lesions, sometimes in association with feline immunodeficiency virus infection.

T2987

985882-985985

Epistemic_statement

denotes

Mitotic activity is present in all layers of the epidermis, and keratin pearl formation may be present.

T2988

985986-986127

Epistemic_statement

denotes

Tumor cells often have large hyperchromatic nuclei and may have vacuolated cytoplasm, cytoplasmic pallor, or occasionally are multinucleated.

T2989

986241-986387

Epistemic_statement

denotes

The tumors are often pigmented and may have papillomatous epidermal projections with marked hyperkeratosis, occasionally forming a cutaneous horn.

T2990

986388-986423

Epistemic_statement

denotes

These lesions may progress to ISCC.

T2991

986424-986503

Epistemic_statement

denotes

Distant metastasis is very rare but was reported in a 7-year-old Devon Rex cat.

T2992

986653-986717

Epistemic_statement

denotes

Papillomaviruses have also been associated with feline sarcoids.

T2993

986718-986852

Epistemic_statement

denotes

These are rare cutaneous neoplasms that tend to occur on the nose, lips, or digits of young to middle-aged cats from rural areas (Fig.

T2994

986862-986932

Epistemic_statement

denotes

Feline sarcoids are firm, smooth, exophytic, and can become ulcerated.

T2995

986933-986994

Epistemic_statement

denotes

Recurrence is common, but metastasis has not been documented.

T2996

986995-987136

Epistemic_statement

denotes

Histologic features virtually identical to the equine sarcoid have been described and found to be associated with papillomavirus DNA via PCR.

T2997

987137-987351

Epistemic_statement

denotes

The implicated virus feline sarcoid-associated PV (FeSarPV) is thought to be a novel bovine papillomavirus (BPV), given the similarity in its DNA sequences to BPV-1, BPV-2, and ovis aries papillomavirus 2 (OaPV-2).

T2998

987362-987458

Epistemic_statement

denotes

Fibropapillomas associated with papillomaviruses have been described in both llamas and alpacas.

T2999

987684-987738

Epistemic_statement

denotes

SCCs are rare in pigs but usually occur in white skin.

T3000

987739-987839

Epistemic_statement

denotes

Rarely, SCC has been reported to arise from burn scars, nonhealing wounds, and chronic inflammation.

T3001

987840-987928

Epistemic_statement

denotes

Brand keratomas in cattle have been reported to undergo malignant transformation to SCC.

T3002

988120-988190

Epistemic_statement

denotes

Equine smegma has been implicated in the development of preputial SCC.

T3003

988687-988721

Epistemic_statement

denotes

Lesions may be single to multiple.

T3004

989030-989280

Epistemic_statement

denotes

The well-differentiated SCC is a plaque-like lesion composed of islands, cords, and trabeculae of squamous cells that originate from the epidermis or rarely hair follicles or follicular cysts, breach the basement membrane, and extend into the dermis.

T3005

989281-989498

Epistemic_statement

denotes

Intercellular bridges between keratinocytes may be prominent, and there is often formation of central accumulations of compact laminated keratin (keratin pearls) within islands of invasive neoplastic epithelial cells.

T3006

989890-989938

Epistemic_statement

denotes

There may be marked crusting and hyperkeratosis.

T3007

990717-990915

Epistemic_statement

denotes

Spindle cell squamous cell carcinoma is a rare variant of poorly differentiated SCC and is composed of large pleomorphic spindle and polygonal cells that have abundant pale or amphophilic cytoplasm.

T3008

990999-991094

Epistemic_statement

denotes

Rare foci of individual cell keratinization will help distinguish this neoplasm from a sarcoma.

T3009

991095-991177

Epistemic_statement

denotes

Verrucous squamous cell carcinoma is a rare variant of SCC only described in dogs.

T3010

991299-991317

Epistemic_statement

denotes

There may species.

T3011

991318-991422

Epistemic_statement

denotes

The behavior of squamous cell carcinoma (SCC) of the skin is usually that of locally destructive spread.

T3012

991423-991506

Epistemic_statement

denotes

Its metastatic potential is low, with certain qualifications depending on location.

T3013

991599-991769

Epistemic_statement

denotes

In contrast, those originating on the canine digit may be more prone to metastasize, but even these are cured by amputation in virtually all but the most neglected cases.

T3014

991770-991919

Epistemic_statement

denotes

Development of SCC has been associated with papillomaviruses in multiple species, including dogs, cats, horses, and sheep (see cutaneous papillomas).

T3015

991920-991999

Epistemic_statement

denotes

Sunlight is probably the most important carcinogenic stimulus for these tumors.

T3016

992000-992154

Epistemic_statement

denotes

The action of sunlight may be related to overexpression of p53 protein as a result of ultraviolet (UV)-induced mutations of the p53 tumor suppressor gene.

T3017

992698-992877

Epistemic_statement

denotes

The nasal planum is rarely affected, and when it is affected, it is usually secondary to depigmentation from a chronic inflammatory condition, such as discoid lupus erythematosus.

T3018

992878-993051

Epistemic_statement

denotes

Subungual squamous cell carcinomas in dogs may be multiple and are seen most often in black dogs, particularly large breeds such as Labrador Retrievers and Standard Poodles.

T3019

993052-993157

Epistemic_statement

denotes

Although papillomaviruses have been a suspected etiology, one study did not support a viral pathogenesis.

T3020

993472-993646

Epistemic_statement

denotes

In goats, Angoras and Boers may be at increased risk, and lesions are most common in sparsely haired skin of the udder, perianal region, horn base, pinnae, vulva, and eyelid.

T3021

993647-993772

Epistemic_statement

denotes

In sheep, cutaneous SCC is most common on the muzzle, lips, eyelids, pinnae, perineum, and vulva, and Merinos may be at risk.

T3022

993953-994079

Epistemic_statement

denotes

Their classification is rather complex; however, the majority of tumors arising in animals share a benign biological behavior.

T3023

995495-995593

Epistemic_statement

denotes

However, in this author's opinion, the report in the alpaca was probably a hybrid follicular cyst.

T3024

996157-996265

Epistemic_statement

denotes

The tumor gradually infiltrates and destroys the horn core and may invade adjacent sinuses and cranial bone.

T3025

996433-996527

Epistemic_statement

denotes

Basal cell carcinomas (BCCs) are uncommon in cats and dogs and rare in other domestic species.

T3026

996528-996631

Epistemic_statement

denotes

These tumors are thought to arise from epithelial cells of the basal layer of the epidermis and adnexa.

T3027

996777-996827

Epistemic_statement

denotes

In cats, chronic UV exposure may also play a role.

T3028

996828-996941

Epistemic_statement

denotes

However, in some cats, BCC arises from BISC, and therefore papillomaviruses may also play a role in pathogenesis.

T3029

996942-996978

Epistemic_statement

denotes

The pathogenesis is unknown in dogs.

T3030

997160-997242

Epistemic_statement

denotes

The skin may have a black or blue tint because of melanin pigment in the neoplasm.

T3031

998266-998325

Epistemic_statement

denotes

Solid BCCs may have small foci of squamous differentiation.

T3032

998381-998472

Epistemic_statement

denotes

Tumor cells may contain melanin, and melanophages may be present in the intervening stroma.

T3033

998473-998603

Epistemic_statement

denotes

Keratinizing basal cell carcinomas have similar features to the solid type; however, melanin and cystic degeneration are uncommon.

T3034

998673-998754

Epistemic_statement

denotes

Mitotic activity is moderate to high, and mitotic atypia can usually be detected.

T3035

998755-998924

Epistemic_statement

denotes

Many of the epithelial islands contain central or peripheral foci of abrupt squamous differentiation that is cytologically benign and may or may not have keratinization.

T3036

998925-998967

Epistemic_statement

denotes

Clear cell basal cell carcinomas are rare.

T3037

999145-999236

Epistemic_statement

denotes

This rare tumor has features of both SCC and BCC and has been described in the cat and dog.

T3038

999596-999710

Epistemic_statement

denotes

Inferior tricholemmomas are very rare, only recognized in dogs, 1-7 cm diameter firm nodules on the head and neck.

T3039

1000069-1000147

Epistemic_statement

denotes

These are thought to represent differentiation toward outer root sheath cells.

T3040

1000274-1000396

Epistemic_statement

denotes

Isthmic tricholemmomas are very rare, raised, alopecic papules and nodules <2 cm in diameter, recognized in cats and dogs.

T3041

1000502-1000587

Epistemic_statement

denotes

Tumors are usually <2 cm in diameter but on occasion can be very large and ulcerated.

T3042

1001151-1001304

Epistemic_statement

denotes

The outer layer of basal cells usually shows peripheral palisading and may abut the fibrous stroma or send out basal cell ribbons into a mucinous stroma.

T3043

1001688-1001750

Epistemic_statement

denotes

Malignant trichoepitheliomas have only been described in dogs.

T3044

1002058-1002155

Epistemic_statement

denotes

Lymphatic invasion is considered an essential finding to confirm malignancy by some pathologists.

T3045

1002156-1002202

Epistemic_statement

denotes

Regional and pulmonary metastasis is possible.

T3046

1002382-1002468

Epistemic_statement

denotes

Other tumors or cysts simulating trichoepithelioma lack one or both of these features.

T3047

1002469-1002584

Epistemic_statement

denotes

Tricholemmoma is a rare, benign, and nonrecurring pilar tumor of the outer root sheath recognized in dogs and cats.

T3048

1002758-1002850

Epistemic_statement

denotes

Tumor cells have scant cytoplasm, oval nuclei with inconspicuous nucleoli, and rare mitoses.

T3049

1002851-1002923

Epistemic_statement

denotes

Melanin may be present in the tumor cells and accompanying melanophages.

T3050

1002924-1002947

Epistemic_statement

denotes

Keratinization is rare.

T3051

1003042-1003183

Epistemic_statement

denotes

These are rare, welldemarcated masses in the dermis to subcutis composed of multiple lobules and trabeculae and areas of cystic degeneration.

T3052

1003447-1003697

Epistemic_statement

denotes

Pilomatricoma (pilomatrixoma, epithelioma of Malherbe, necrotizing and calcifying epithelioma) is an uncommon benign tumor of dogs and is believed to be derived from primitive hair matrix and thus shows incomplete differentiation towards hair cortex.

T3053

1004682-1004729

Epistemic_statement

denotes

Small zones of squamous epithelium may be seen.

T3054

1004730-1004823

Epistemic_statement

denotes

Small foci resembling rounded dermal papilla-like structures may be present in the cyst wall.

T3055

1004931-1005048

Epistemic_statement

denotes

Mitotic activity may arranged as islands, and radiating cords that may intersect or be associated with the epidermis.

T3056

1005240-1005333

Epistemic_statement

denotes

These are common in dogs and cats, seen occasionally in horses, and rare in cattle and sheep.

T3057

1005334-1005473

Epistemic_statement

denotes

Lesions are generally solitary, firm, raised alopecic nodules 1-2 cm in diameter, although they can sometimes be much larger and ulcerated.

T3058

1005771-1005854

Epistemic_statement

denotes

6 -148) that may join or radiate from a large central aggregate (medusoid pattern).

T3059

1005855-1005924

Epistemic_statement

denotes

A mucinous stroma is frequently associated with the medusoid pattern.

T3060

1006019-1006051

Epistemic_statement

denotes

Mitotic figures may be numerous.

T3061

1006052-1006126

Epistemic_statement

denotes

Abundant collagen that may appear hyalinized is more common in dog tumors.

T3062

1006127-1006193

Epistemic_statement

denotes

This pattern is common in dogs and rare in cats and other species.

T3063

1006476-1006554

Epistemic_statement

denotes

Stroma is sparse and may be collagenous to mucinous and is of low cellularity.

T3064

1006555-1006589

Epistemic_statement

denotes

Keratin microcysts may be present.

T3065

1006631-1006839

Epistemic_statement

denotes

• Granular trichoblastoma is a rare variant with the same architecture as a ribbon trichoblastoma, but the neoplastic epithelial cells are larger and contain abundant, finely granular or vacuolated cytoplasm.

T3066

1007358-1007430

Epistemic_statement

denotes

As in nodular hyperplasia, perianal gland metaplasia is rarely observed.

T3067

1007431-1007479

Epistemic_statement

denotes

There may be compression of adjacent structures.

T3068

1007867-1007972

Epistemic_statement

denotes

Mitotic activity may be high in the basal reserve cells, but mature sebocytes are not mitotically active.

T3069

1008042-1008115

Epistemic_statement

denotes

These lesions, especially Meibomian epitheliomas, are variably pigmented.

T3070

1008171-1008404

Epistemic_statement

denotes

Sebaceous and Meibomian epitheliomas may recur if incompletely excised; rarely, sebaceous epitheliomas have been reported to invade lymphatics and metastasize to regional lymph nodes and, in one case, lung and central nervous system.

T3071

1008405-1008472

Epistemic_statement

denotes

Sebaceous carcinomas are rare malignant neoplasms in dogs and cats.

T3072

1008473-1008508

Epistemic_statement

denotes

Cocker Spaniels may be predisposed.

T3073

1008749-1008885

Epistemic_statement

denotes

Sebocytic carcinomas are multilobular dermal masses that are irregular in shape but well circumscribed and may extend into the subcutis.

T3074

1009055-1009144

Epistemic_statement

denotes

Neoplastic cells are pleomorphic with eosinophilic cytoplasm that is variably vacuolated.

T3075

1009229-1009267

Epistemic_statement

denotes

There may be atypical mitotic figures.

T3076

1009268-1009420

Epistemic_statement

denotes

Other possible features include ulceration, necrosis, cystic degeneration, squamous differentiation, keratinization, or occasional glandular structures.

T3077

1009984-1010112

Epistemic_statement

denotes

Malignant pilomatricomas (matrical carcinoma, pilomatrix carcinoma) are rare in dogs and not reported in other domestic species.

T3078

1010113-1010276

Epistemic_statement

denotes

They are locally aggressive and may invade bone, and have been reported to metastasize to multiple distant sites, including lung, central nervous system, and bone.

T3079

1010277-1010357

Epistemic_statement

denotes

This malignant variant is poorly circumscribed and may extend into the subcutis.

T3080

1011669-1011755

Epistemic_statement

denotes

Sebaceous gland tumors are common in dogs, uncommon in cats and rare in other species.

T3081

1013294-1013321

Epistemic_statement

denotes

Small ducts may be present.

T3082

1013991-1014102

Epistemic_statement

denotes

Nuclei are larger than those in benign lesions, slightly pleomorphic, and may have multiple prominent nucleoli.

T3083

1014188-1014245

Epistemic_statement

denotes

There may be small scattered foci of squamous metaplasia.

T3084

1014295-1014333

Epistemic_statement

denotes

Poorly differentiated tumors are rare.

T3085

1014447-1014535

Epistemic_statement

denotes

Neoplastic cells have eosinophilic to amphophilic cytoplasm that is variably vacuolated.

T3086

1014640-1014813

Epistemic_statement

denotes

Lymphatic invasion must be diagnosed with caution because compression of reserve cells by lobular expansion may simulate a tumor embolus surrounded by lymphatic endothelium.

T3087

1014943-1014992

Epistemic_statement

denotes

Direct extension into the pelvic canal can occur.

T3088

1015057-1015120

Epistemic_statement

denotes

Epitrichial (apocrine) gland tumors can be benign or malignant.

T3089

1015121-1015210

Epistemic_statement

denotes

Adenomas are more common and occur in cats, dogs, and rarely in horses, cattle, and pigs.

T3090

1015276-1015312

Epistemic_statement

denotes

Cystic tumors may be blue to purple.

T3091

1015510-1015602

Epistemic_statement

denotes

Carcinomas more commonly occur on the legs and may be poorly circumscribed and infiltrative.

T3092

1015975-1016122

Epistemic_statement

denotes

Some cysts contain simple or branching papillary aggregates, and if this is a dominant feature, then the term papillary cystadenoma is appropriate.

T3093

1016123-1016165

Epistemic_statement

denotes

Small glandular structures may be present.

T3094

1016166-1016328

Epistemic_statement

denotes

In cats, the majority of these tumors are on the head, including ear canal and eyelid (glands of Moll), and lesions may be multiple in Himalayan and Persian cats.

T3095

1016451-1016549

Epistemic_statement

denotes

Cystic cavities and glandular lumens may contain pale eosinophilic homogeneous secretory material.

T3096

1016550-1016656

Epistemic_statement

denotes

Complex (mixed) secretory epitrichial adenomas are analogous to complex and benign mixed mammary adenomas.

T3097

1016744-1016797

Epistemic_statement

denotes

There may be multifocal connections to the epidermis.

T3098

1016798-1016892

Epistemic_statement

denotes

They are commonly ulcerated, and margins may be infiltrative and can extend into the subcutis.

T3099

1017144-1017218

Epistemic_statement

denotes

They may be locally aggressive but reports of distant metastasis are rare.

T3100

1017219-1017371

Epistemic_statement

denotes

The cause of perianal gland tumors is unknown; however, they are known to be modulated by sex hormones and contain both androgen and estrogen receptors.

T3101

1017372-1017506

Epistemic_statement

denotes

Nodular perianal gland hyperplasia may occur as either discrete nodules of variable size or as a diffuse bulging ring around the anus.

T3102

1017821-1018028

Epistemic_statement

denotes

The gross appearance of perianal gland adenomas is of one or more raised rubbery masses that may grow to 10 cm or more in diameter, most commonly around the anus but can occur anywhere perianal glands exist.

T3103

1018424-1018615

Epistemic_statement

denotes

Distinguishing adenomas from hyperplasia can be difficult, but the main difference is that the lobular architecture is maintained in hyperplastic lesions, and adenomas may be highly vascular.

T3104

1018616-1018716

Epistemic_statement

denotes

Perianal (hepatoid) gland epitheliomas are rare tumors and may be benign or of low-grade malignancy.

T3105

1019562-1019600

Epistemic_statement

denotes

Multinucleated cells are usually seen.

T3106

1019658-1019729

Epistemic_statement

denotes

There is sparse to moderate stroma, and chondroid metaplasia may occur.

T3107

1019848-1019971

Epistemic_statement

denotes

Immunohistochemistry using specific cytokeratin such as CAM5.2, CK7/8, and CK13 may be necessary to support this diagnosis.

T3108

1020052-1020156

Epistemic_statement

denotes

Tumors of atrichial (eccrine) glands are extremely rare and occur only on the footpads of dogs and cats.

T3109

1020157-1020231

Epistemic_statement

denotes

These tumors are usually malignant, although a few adenomas are described.

T3110

1020232-1020334

Epistemic_statement

denotes

Lesions are usually poorly circumscribed, ulcerated, and may be seen as swollen pawpad(s) or digit(s).

T3111

1020335-1020440

Epistemic_statement

denotes

These are aggressive neoplasms that often recur locally and may metastasize rapidly to local lymph nodes.

T3112

1020481-1020587

Epistemic_statement

denotes

Histologically, they are infiltrative, have desmoplastic stroma, and may invade bone and cause bone lysis.

T3113

1020842-1020984

Epistemic_statement

denotes

Ceruminous glands can give rise to cysts, cystomatosis, adenomas, complex and mixed adenomas, and the malignant versions of these tumors (Fig.

T3114

1021197-1021318

Epistemic_statement

denotes

In addition, foci of tumor cells may be found within the overlying epithelium, and secondary inflammation is more common.

T3115

1021319-1021374

Epistemic_statement

denotes

Stroma may be myxoid or have chondroid differentiation.

T3116

1021881-1021977

Epistemic_statement

denotes

The centers of the lobules may be irregularly cystic and partially lined by cuboidal epithelium.

T3117

1022687-1022761

Epistemic_statement

denotes

Lesions are generally solitary, frequently alopecic, and may be ulcerated.

T3118

1022848-1023033

Epistemic_statement

denotes

In general, these lesions are histologically similar to their benign counterparts, although they tend to be larger and less well circumscribed and have cytologic features of malignancy.

T3119

1023034-1023143

Epistemic_statement

denotes

Nuclei are larger and more pleomorphic; there may be loss of nuclear polarity, and nucleoli may be prominent.

T3120

1023169-1023206

Epistemic_statement

denotes

Atypical mitotic figures may be seen.

T3121

1023207-1023306

Epistemic_statement

denotes

Well-differentiated lesions do not produce a desmoplastic response, and lymphatic invasion is rare.

T3122

1023425-1023526

Epistemic_statement

denotes

The myoepithelial component of the complex adenocarcinoma usually has a benign histologic appearance.

T3123

1023527-1023597

Epistemic_statement

denotes

However, in some cases, it predominates over the epithelial component.

T3124

1023598-1023808

Epistemic_statement

denotes

On rare occasions, both glandular and myoepithelial components demonstrate features of malignancy, and the tumor is referred to as an epitrichial gland carcinosarcoma or mixed malignant epitrichial gland tumor.

T3125

1023889-1024048

Epistemic_statement

denotes

They have been reported in most species of domestic animals and many wildlife species, although they are most common in dogs, horses, and some breeds of swine.

T3126

1024049-1024114

Epistemic_statement

denotes

component may form whorls and fingerprint patterns in the dermis.

T3127

1024267-1024370

Epistemic_statement

denotes

Mitotic figures are rare, and in the dog, a mitotic index of <3 is reported to predict benign behavior.

T3128

1024615-1024693

Epistemic_statement

denotes

Fine melanin granules can sometimes be detected in low numbers of tumor cells.

T3129

1024852-1024950

Epistemic_statement

denotes

It is well described in humans but is rare in domestic animals and has been reported only in dogs.

T3130

1025487-1025615

Epistemic_statement

denotes

Malignant melanomas are generally tumors of older animals; however, they have been reported in juvenile animals of many species.

T3131

1025616-1025811

Epistemic_statement

denotes

Criteria for malignancy and prognosis are described in the introduction to this section; in the dog, a mitotic index of 3 or greater appears to be the most accurate predictor of a poor prognosis.

T3132

1025812-1025949

Epistemic_statement

denotes

In addition, several studies have indicated that the degree of pigmentation and the histologic pattern are not correlated with prognosis.

T3133

1025950-1026165

Epistemic_statement

denotes

Malignant melanomas can be composed of a variety of cell morphologies, including spindle cells, epithelioid cells, a mixture of spindle cells and epithelioid cells, signet-ring cells, or balloon cells (clear cells).

T3134

1026283-1026376

Epistemic_statement

denotes

Focal areas of chondroid or osseous metaplasia within the tumor may be seen on rare occasion.

T3135

1026582-1026712

Epistemic_statement

denotes

Various degrees of junctional activity may be present in the epithelioid cell form and in the mixed epithelioid-spindle cell form.

T3136

1027147-1027351

Epistemic_statement

denotes

An infrequent form of spindle cell melanoma, composed entirely of amelanotic spindle cells, can be impossible to distinguish from fibrosarcoma or neurofibrosarcoma without the aid of immunohistochemistry.

T3137

1027352-1027551

Epistemic_statement

denotes

Although the epithelioid and spindle cell forms of melanoma are usually pigmented to some degree, the uncommon balloon cell form and signet-ring cell form are usually unpigmented or poorly pigmented.

T3138

1027552-1027694

Epistemic_statement

denotes

current recommendation is to perform immunohistochemical labeling with Melan-A, PNL2, TRP-1, and TRP-2 as single antibodies, or as a cocktail.

T3139

1027695-1027857

Epistemic_statement

denotes

The mitotic index (MI) is a key prognostic indicator for clinical behavior of canine melanocytic neoplasms, and it should be determined on all melanocytic tumors.

T3140

1028096-1028132

Epistemic_statement

denotes

Ulcerated regions should be avoided.

T3141

1028294-1028486

Epistemic_statement

denotes

Currently, Melan A is the most specific immunohistochemical marker for melanomas, albeit not 100% sensitive, and has been shown to be useful in many species, including the dog, cat, and horse.

T3142

1028487-1028603

Epistemic_statement

denotes

Dogs with cutaneous melanocytic neoplasms that have an MI of >3/10 HPFs are expected to have shorter survival times.

T3143

1028604-1028862

Epistemic_statement

denotes

Nuclear atypia, presence of ulceration, and deep infiltration beyond the dermis are also associated with a poor outcome, and readers are referred to the publication by Smedley (2011) for more detailed information and a thorough review of prognostic features.

T3144

1029295-1029458

Epistemic_statement

denotes

Histologically, melanocytomas can be junctional (confined to the epidermis and dermoepidermal junction), compound (involving both epidermis and dermis), or dermal.

T3145

1029544-1029722

Epistemic_statement

denotes

They are moderately circumscribed but not encapsulated and may be composed of any melanocytic cell type, that is, spindle, epithelioid, balloon cell (clear cell), or signet ring.

T3146

1030071-1030234

Epistemic_statement

denotes

A report of a myxoma developing at the site of a subcutaneously implanted pacemaker in a dog raised the question of whether the implant may have induced the tumor.

T3147

1030452-1030554

Epistemic_statement

denotes

Cellularity is typically low, and the cells have small hyperchromatic nuclei and rare mitotic figures.

T3148

1030620-1030768

Epistemic_statement

denotes

Myxomas are difficult to differentiate from myxosarcomas because both are poorly circumscribed, locally infiltrative, and have low mitotic activity.

T3149

1030769-1030887

Epistemic_statement

denotes

However, nuclear and cellular pleomorphism is more apparent, and atypical mitotic figures may be seen in myxosarcomas.

T3150

1031390-1031508

Epistemic_statement

denotes

A large battery of immunohistochemical stains is necessary to differentiate the subtypes, but is generally not needed.

T3151

1031947-1032083

Epistemic_statement

denotes

They are usually solitary, slow-growing, multinodular masses that appear grossly well circumscribed and measure up to 25 cm in diameter.

T3152

1032163-1032345

Epistemic_statement

denotes

The tumors frequently recur following excision because of the difficulty in identifying tumor margins and inability to perform wide surgical excision because of anatomic constraints.

T3153

1032346-1032378

Epistemic_statement

denotes

Metastasis is uncommon, however.

T3154

1032993-1033106

Epistemic_statement

denotes

Aggregates of lymphocytes may be scattered within some tumors and are usually most prominent along the periphery.

T3155

1033107-1033341

Epistemic_statement

denotes

At the margins of the tumor, finger-like microextensions of tumor cells commonly infiltrate along fascial planes and are the reason many tumors are incompletely excised despite the clinical impression that they are well circumscribed.

T3156

1033838-1033934

Epistemic_statement

denotes

Adnexal structures are absent, and mononuclear inflammatory cells may be present in low numbers.

T3157

1034445-1034549

Epistemic_statement

denotes

Collagenous hamartomas are usually located in the dermis, but large masses may extend into the subcutis.

T3158

1034743-1034846

Epistemic_statement

denotes

Some veterinary pathologists believe that collagen hamartomas are actually fibromas of low cellularity.

T3159

1034847-1035174

Epistemic_statement

denotes

A syndrome called nodular dermatofibrosis, characterized by multiple cutaneous collagenous hamartomas, has been reported as a marker of renal epithelial neoplasia in German Shepherd dogs (see also the previous section Cutaneous paraneoplastic syndromes).The condition is thought to be inherited in an autosomal dominant manner.

T3160

1035252-1035324

Epistemic_statement

denotes

Nodules may number in the hundreds and are located anywhere on the body.

T3161

1035824-1035876

Epistemic_statement

denotes

They are usually alopecic and may be hyperpigmented.

T3162

1035877-1035927

Epistemic_statement

denotes

Large tumors may be ulcerated secondary to trauma.

T3163

1036073-1036274

Epistemic_statement

denotes

The fibroblasts have uniform, oval to elongate, bland nuclei that may be slightly larger than fibroblasts in the normal dermis and have fine chromatin, inconspicuous nucleoli, and rare mitotic figures.

T3164

1036509-1036667

Epistemic_statement

denotes

Some tumors contain substantial amounts of mucinous or myxomatous matrix material in addition to the collagen, in which case the term fibromyxoma may be used.

T3165

1036817-1036979

Epistemic_statement

denotes

Myxomas (myxofibromas) are rare cutaneous neoplasms arising from fibroblasts or multipotential mesenchymal cells and containing abundant glycosaminoglycan stroma.

T3166

1036980-1037146

Epistemic_statement

denotes

They usually occur in adult or aged animals as solitary, infiltrative, soft masses that are poorly circumscribed and may extend along may be involved most frequently.

T3167

1037147-1037237

Epistemic_statement

denotes

Schwannomas are usually subcutaneous in dogs; in cats, they may be confined to the dermis.

T3168

1037553-1037661

Epistemic_statement

denotes

A delicate collagenous stroma is moderately abundant, and a mucinous matrix may be prominent in some tumors.

T3169

1037964-1038085

Epistemic_statement

denotes

Mitotic figures are uncommon in benign tumors but may be moderately numerous in malignant peripheral nerve sheath tumors.

T3170

1038086-1038243

Epistemic_statement

denotes

Histologically and behaviorally, peripheral nerve sheath tumors may be difficult to differentiate from fibromas, well-differentiated fibrosarcomas, and PWTs.

T3171

1038244-1038427

Epistemic_statement

denotes

However, neural tumors express S-100 protein, myelin basic protein, neuronspecific enolase, and glial fibrillary acidic protein, whereas the other more common cutaneous tumors do not.

T3172

1038428-1038561

Epistemic_statement

denotes

In dogs, malignant peripheral nerve sheath tumors may arise within the peripheral nervous system (PNS) or within non-PNS soft tissue.

T3173

1038710-1038869

Epistemic_statement

denotes

Tumors arising within peripheral nerves have been shown to have higher S-100 and Olig 2 expression than peripheral nerve sheaths tumors arising in soft tissue.

T3174

1038870-1039130

Epistemic_statement

denotes

Immunohistochemical staining of granular cell tumors (granular cell myoblastomas) has demonstrated S-100 protein, myelin basic protein, and neuron-specific enolase within tumor cells, suggesting that they also represent a form of peripheral nerve sheath tumor.

T3175

1039321-1039428

Epistemic_statement

denotes

In veterinary medicine, this lesion is rare and occurs most frequently as a result of tail docking in dogs.

T3176

1040228-1040306

Epistemic_statement

denotes

The size of the tumors has been associated with increased relapse probability.

T3177

1040397-1040485

Epistemic_statement

denotes

Fortunately, cases in any profile with complete surgical margins typically do not recur.

T3178

1040536-1040626

Epistemic_statement

denotes

PWTs should be differentiated from fibrosarcomas, rhabdomyosarcomas, and hemangiosarcomas.

T3179

1040627-1040804

Epistemic_statement

denotes

Cutaneous tumors of neural origin are uncommon in domestic animals but are likely under-diagnosed because of their histologic similarity to other more common tumors of the skin.

T3180

1040919-1041113

Epistemic_statement

denotes

Consequently, these tumors are histologically heterogeneous, and the histogenesis is frequently uncertain, resulting in various and confusing classifications and terminologies in the literature.

T3181

1041237-1041481

Epistemic_statement

denotes

The name peripheral nerve sheath tumor is a broad term proposed to include all tumors arising from peripheral nerves; however, because most tumors are composed of Schwann cells, the term schwannoma is appropriate for the majority of the tumors.

T3182

1041482-1041586

Epistemic_statement

denotes

Both benign and malignant forms occur; however, tumors that appear histologically benign commonly recur.

T3183

1041587-1041681

Epistemic_statement

denotes

Schwannomas are common in cattle but occur primarily in the heart and rarely involve the skin.

T3184

1041682-1041786

Epistemic_statement

denotes

A condition termed neurofibromatosis has been observed in cattle of all ages and may occur congenitally.

T3185

1043483-1043611

Epistemic_statement

denotes

These microscopic extensions of the tumor account for the difficulty in excising the tumor completely and resultant recurrences.

T3186

1043612-1043706

Epistemic_statement

denotes

Although collagen is the primary stromal element, mucin may also be produced in small amounts.

T3187

1043923-1044025

Epistemic_statement

denotes

In dogs, a mitotic index <9 was associated with greater survival than a mitotic index of 9 or greater.

T3188

1044201-1044487

Epistemic_statement

denotes

Poorly differentiated fibrosarcomas may be difficult to differentiate from a number of other mesenchymal and nonmesenchymal tumors, including malignant schwannoma, malignant fibrous histiocytoma, leiomyosarcoma, and spindle cell forms of amelanotic melanoma and squamous cell carcinoma.

T3189

1044646-1044792

Epistemic_statement

denotes

In small biopsies with a limited amount of tissue to evaluate, it may be difficult to differentiate fibrosarcoma from reactive granulation tissue.

T3190

1045692-1046019

Epistemic_statement

denotes

It was originally believed to be derived from malignant cells of monocyte-macrophage origin capable of acting as "facultative" traumatic neuromas are well-circumscribed nodules composed of haphazardly arranged myelinated nerve bundles of variable size randomly distributed within a relatively abundant connective tissue stroma.

T3191

1046020-1046122

Epistemic_statement

denotes

Fibrosarcomas are malignant tumors of fibroblasts that show no other evidence of cell differentiation.

T3192

1046123-1046163

Epistemic_statement

denotes

They commonly recur and may metastasize.

T3193

1046164-1046374

Epistemic_statement

denotes

Fibrosarcomas are undoubtedly over-diagnosed, as virtually any anaplastic highly cellular spindle cell sarcoma containing collagen is diagnosed as a fibrosarcoma when more specific histogenesis is not apparent.

T3194

1046375-1046673

Epistemic_statement

denotes

However, as immunohistochemistry has become a routine technique in most diagnostic laboratories, fibrosarcoma can be separated from other spindle cell tumors, such as peripheral nerve sheath tumor, leiomyosarcoma, rhabdomyosarcoma, amelanotic malignant melanoma, spindle cell carcinoma, and others.

T3195

1046845-1046973

Epistemic_statement

denotes

They usually arise in the subcutis and are poorly circumscribed masses of variable size that may be soft to firm in consistency.

T3196

1047132-1047321

Epistemic_statement

denotes

Similarities have been noted between canine fibrosarcomas from presumed injection sites and feline postvaccinal fibrosarcomas, suggesting that postinjection sarcomas may also occur in dogs.

T3197

1047498-1047533

Epistemic_statement

denotes

Virus-induced fibrosarcoma is rare.

T3198

1048119-1048161

Epistemic_statement

denotes

These may arise in the dermis or subcutis.

T3199

1048369-1048564

Epistemic_statement

denotes

Epidemiologic evidence supports a relationship between vaccine administration in cats and the development of postvaccinal fibrosarcomas and, to a lesser extent, other sarcomas in injection sites.

T3200

1048736-1048987

Epistemic_statement

denotes

The mechanism of tumor development is unknown, but persistent injection-site-induced inflammation leading to deranged fibrous connective tissue repair response and eventual neoplastic transformation in genetically predisposed cats has been postulated.

T3201

1048988-1049077

Epistemic_statement

denotes

Alterations in oncogene and growth factor expression may be involved in the pathogenesis.

T3202

1049930-1049955

Epistemic_statement

denotes

Mitotic figures are rare.

T3203

1050145-1050237

Epistemic_statement

denotes

Smooth muscle tumors may be confused with fibromas, fibrosarcomas, or malignant schwannomas.

T3204

1050238-1050329

Epistemic_statement

denotes

In such cases, immunohistochemical staining for actin and desmin can confirm muscle origin.

T3205

1050330-1050422

Epistemic_statement

denotes

Cutaneous tumors of skeletal muscle, rhabdomyomas and rhabdomyosarcomas, are extremely rare.

T3206

1050779-1050805

Epistemic_statement

denotes

Mitotic figures were rare.

T3207

1050866-1050940

Epistemic_statement

denotes

Lesions can appear as red to purple macules, papules, nodules, or plaques.

T3208

1051105-1051152

Epistemic_statement

denotes

has been described in an immunocompromised dog.

T3209

1051153-1051365

Epistemic_statement

denotes

Multisystem progressive angiomatosis affecting the skin, gastrointestinal tract, and visceral surface of the abdominal organs, a syndrome resembling blue rubber bleb nevus syndrome, has been described in one dog.

T3210

1051446-1051629

Epistemic_statement

denotes

Hemangiosarcoma, the malignant form of a tumor of blood vessel endothelium, can occur in the skin as a primary site or as a result of metastatic disease from a primary visceral tumor.

T3211

1051847-1052122

Epistemic_statement

denotes

Cutaneous hemangiosarcoma commonly recurs following excision and has the potential for widespread local invasion and metastasis; but in general, it appears to be less aggressive, has a longer clinical course, and prolonged survival when compared to visceral hemangiosarcomas.

T3212

1052123-1052229

Epistemic_statement

denotes

In contrast to the subcutaneous form, dermal hemangiosarcoma may be cured by wide surgical excision alone.

T3213

1052765-1052794

Epistemic_statement

denotes

Mitotic activity may be high.

T3214

1052795-1053041

Epistemic_statement

denotes

Frequently, portions or entire tumors are composed entirely of sheets or intersecting and anastomosing bundles of pleomorphic spindle cells, and they may be indistinguishable from fibrosarcoma or other poorly differentiated spindle cell sarcomas.

T3215

1053042-1053157

Epistemic_statement

denotes

The presence of slit-like spaces containing erythrocytes between tumor cells may be the only clue to the diagnosis.

T3216

1053158-1053246

Epistemic_statement

denotes

Immunohistochemical staining may be required to identify the cells in anaplastic tumors.

T3217

1053399-1053660

Epistemic_statement

denotes

However, immunostaining must be interpreted with knowledge of limitations of the procedure; in poorly differentiated tumors, very anaplastic cells may not express typical antigens, and immature reactive stromal endothelial cells may be mistaken for tumor cells.

T3218

1053661-1053743

Epistemic_statement

denotes

Tumors arising from endothelium of lymphatic vessels are rare in domestic animals.

T3219

1053744-1054025

Epistemic_statement

denotes

Both the benign, lymphangioma, and malignant, lymphangiosarcoma, forms occur in young animals, and it has been suggested that they represent lymphatic malformations resulting from a failure of connection between lymph vessels and the venous system rather than being true neoplasms.

T3220

1054026-1054193

Epistemic_statement

denotes

The skin and subcutis appear to be the most common site of tumors of lymphatic endothelium, and the caudal ventral abdomen and inguinal areas appear to be predisposed.

T3221

1054335-1054398

Epistemic_statement

denotes

Rarely, they occur as multiple clear turgid vesicles or bullae.

T3222

1054399-1054520

Epistemic_statement

denotes

It may be difficult to distinguish between lymphangioma and lymphangiosarcoma in this location, and they may be multiple.

T3223

1054552-1054775

Epistemic_statement

denotes

Benign cutaneous vascular lesions in horses frequently occur in animals <1 year of age, and some are congenital, raising the question of whether the lesions are true neoplasms or vascular malformations (hamartoma or nevus).

T3224

1054989-1055149

Epistemic_statement

denotes

The lesions are most commonly located on the limbs and occur as a cauliflower or nodular mass or diffuse skin thickening that may become alopecic and ulcerated.

T3225

1055150-1055191

Epistemic_statement

denotes

The lesions may recur following excision.

T3226

1055636-1055661

Epistemic_statement

denotes

Mitotic figures are rare.

T3227

1055662-1055824

Epistemic_statement

denotes

Subcutaneous tumors are usually well circumscribed, whereas those in the dermis may not be as well defined and may incorporate adnexal structures within the mass.

T3228

1056181-1056312

Epistemic_statement

denotes

Solar-induced dermal hemangiomas of glabrous skin are located in the superficial dermis and may be associated with solar elastosis.

T3229

1057367-1057498

Epistemic_statement

denotes

DCs and macrophages have overlapping functions in that both can function as antigen-presenting cells and can act as effector cells.

T3230

1057724-1057914

Epistemic_statement

denotes

The morphologic features of neoplastic or abnormally reactive histiocytes are similar and can mimic tumor cells of different histogenic origin or be confused with granulomatous inflammation.

T3231

1058276-1058419

Epistemic_statement

denotes

More than 70% of CCH occur in dogs <4 years of age and are most often found on the head (pinna), but can occur anywhere on the body at any age.

T3232

1059210-1059339

Epistemic_statement

denotes

The epidermis is often attenuated or ulcerated, and associated edema may lead to vertical rowing of tumor cells near the surface.

T3233

1059340-1059397

Epistemic_statement

denotes

Ulceration is associated with infiltrates of neutrophils.

T3234

1059398-1059439

Epistemic_statement

denotes

The intact epidermis may be hyperplastic.

T3235

1059547-1059706

Epistemic_statement

denotes

Nuclei are centrally located, round to oval, indented or convoluted with vesicular chromatin, and most often have a single nucleolus that may be inconspicuous.

T3236

1059783-1059912

Epistemic_statement

denotes

The base of the tumor may have infiltrates of CD8+ cytotoxic T lymphocytes, a sign of host-mediated spontaneous tumor regression.

T3237

1059913-1059997

Epistemic_statement

denotes

Infiltrates of lymphocytes may also be found in perivascular or periadnexal regions.

T3238

1059998-1060219

Epistemic_statement

denotes

In older lesions, the lymphocytic infiltrates may be more extensive than the remaining tumor cell infiltrates, leading to a misinterpretation of primary inflammatory process or inflamed nonepitheliotropic T-cell lymphoma.

T3239

1060351-1060544

Epistemic_statement

denotes

As the function of LCs is to capture antigen and migrate to regional lymph nodes, regional lymph nodes may be enlarged but are not painful and should regress to normal size after tumor removal.

T3240

1060545-1060657

Epistemic_statement

denotes

histologically because the histologic appearance may not correlate well with the biologic behavior of the tumor.

T3241

1060658-1060742

Epistemic_statement

denotes

Tumors that appear histologically benign commonly recur and may be locally invasive.

T3242

1060838-1060945

Epistemic_statement

denotes

They are poorly defined and difficult to remove completely, resulting in poor wound healing and recurrence.

T3243

1061077-1061190

Epistemic_statement

denotes

They may contain only small amounts of proteinaceous fluid and low numbers of erythrocytes and/or lymphoid cells.

T3244

1061191-1061318

Epistemic_statement

denotes

The connective tissue stroma separating the vascular spaces is loose or edematous and may contain aggregates of lymphoid cells.

T3245

1061458-1061655

Epistemic_statement

denotes

Ulceration, hemorrhage, granulation tissue proliferation, and inflammation are frequently present because of the chronic clinical course and may result in misdiagnosis when a small biopsy is taken.

T3246

1061656-1061759

Epistemic_statement

denotes

It may not be possible to differentiate a poorly differentiated lymphangiosarcoma from hemangiosarcoma.

T3247

1062422-1062511

Epistemic_statement

denotes

The tumors are markedly infiltrative, difficult to completely excise, and commonly recur.

T3248

1062512-1062531

Epistemic_statement

denotes

Metastasis is rare.

T3249

1063142-1063223

Epistemic_statement

denotes

Lesions may wax and wane, and the minority of cases of CRH spontaneously regress.

T3250

1063224-1063405

Epistemic_statement

denotes

Many times, the lesions are slowly progressive and require long-term management with immunomodulatory therapy and often lead to death, particularly if there is systemic involvement.

T3251

1063406-1063616

Epistemic_statement

denotes

Histiocytic sarcoma (HS) complex includes a number of distinct syndromes: hemophagocytic HS, articular/periarticular HS, central nervous system HS, dendritic cell leukemia, and feline progressive histiocytosis.

T3252

1063740-1063841

Epistemic_statement

denotes

Histiocytic sarcomas can be localized, affecting one site, or disseminated (malignant histiocytosis).

T3253

1063988-1064037

Epistemic_statement

denotes

The condition occurs in dogs and is rare in cats.

T3254

1064406-1064464

Epistemic_statement

denotes

Mild nonregenerative anemia and hypercalcemia may be seen.

T3255

1065385-1065542

Epistemic_statement

denotes

It is unclear whether the disseminated histiocytic sarcoma represents metastasis of a primary lesion or multicentric malignant transformation of histiocytes.

T3256

1065692-1065737

Epistemic_statement

denotes

Cutaneous involvement is rare with this form.

T3257

1066145-1066210

Epistemic_statement

denotes

They may also express E-cadherin, lysozyme, CD11d/CD18, and CD54.

T3258

1066211-1066352

Epistemic_statement

denotes

Affected dogs may have hundreds of raised, red, alopecic, and ulcerated cutaneous papules and nodules that are histologically similar to CCH.

T3259

1066353-1066417

Epistemic_statement

denotes

Lesions may involve mucocutaneous junctions and the oral cavity.

T3260

1066418-1066544

Epistemic_statement

denotes

Lesions are generally limited to skin and draining lymph nodes initially, but spread to internal organs can also occur rarely.

T3261

1066973-1067107

Epistemic_statement

denotes

Histologically, lesions are similar to those of CCH; however, individual lesions may be larger extending into the subcutis and muscle.

T3262

1067108-1067241

Epistemic_statement

denotes

Also there may be a high degree of cellular atypia with more anisocytosis and multinucleated cells and a lack of T-cell infiltration.

T3263

1067242-1067271

Epistemic_statement

denotes

Lymphatic invasion may occur.

T3264

1067679-1067773

Epistemic_statement

denotes

Lesions may wax and wane, disappear and reappear in other locations, or spontaneously regress.

T3265

1068195-1068342

Epistemic_statement

denotes

It generally affects young to middle-aged dogs, and although it was first described in Bernese Mountain dogs, it has been described in many breeds.

T3266

1068428-1068531

Epistemic_statement

denotes

Clinical signs may include anorexia, weight loss, conjunctivitis, chemosis, and stertorous respiration.

T3267

1068532-1068567

Epistemic_statement

denotes

Lesions and signs may wax and wane.

T3268

1068838-1069015

Epistemic_statement

denotes

Dermal interstitial DC and T cells infiltrate blood vessel walls in the mid-dermis, leading to lymphohistiocytic vasculitis, which may cause vascular compromise and infarction .

T3269

1069016-1069063

Epistemic_statement

denotes

Lymphocytes may comprise 50% of the infiltrate.

T3270

1069064-1069146

Epistemic_statement

denotes

Smaller numbers of neutrophils, plasma cells, and eosinophils may also be present.

T3271

1069295-1069389

Epistemic_statement

denotes

Older lesions extend into the more superficial dermis and may have a periadnexal distribution.

T3272

1069775-1070001

Epistemic_statement

denotes

As heavy accumulations of mast cells may occur in a variety of parasitic, mycotic, allergic, and idiopathic inflammatory syndromes, caution is warranted; however, sheets of mast cells are not present in these other conditions.

T3273

1070002-1070223

Epistemic_statement

denotes

Multiple spontaneously regressing mast cell tumors have been reported in young dogs, cats, pigs, calves, foals, and humans, suggesting the underlying process may have been mast cell hyperplasia rather than true neoplasia.

T3274

1071137-1071232

Epistemic_statement

denotes

Ulceration in large or traumatized tumors may bring the skin surface in contact with the tumor.

T3275

1071266-1071393

Epistemic_statement

denotes

Edema may be very severe, giving the tumor an appearance that macroscopically and microscopically resembles acute inflammation.

T3276

1071637-1071697

Epistemic_statement

denotes

Degenerating collagen may incite granulomatous inflammation.

T3277

1071698-1071749

Epistemic_statement

denotes

Collagen flame figures may be found in some tumors.

T3278

1071750-1071896

Epistemic_statement

denotes

In dogs, mast cell tumors (MCTs) account for 15-20% of skin tumors and are the most frequent malignant or potentially malignant tumor of the skin.

T3279

1072205-1072346

Epistemic_statement

denotes

The macroscopic appearance of canine mast cell tumors varies widely with their stage of progression and degree of histologic differentiation.

T3280

1072347-1072514

Epistemic_statement

denotes

Well-differentiated tumors most often appear as a rubbery, nodular nonencapsulated variably alopecic dermal mass 1-4 cm in diameter that clinically resembles a lipoma.

T3281

1072515-1072717

Epistemic_statement

denotes

Poorly differentiated tumors tend to achieve a large size more quickly, are less circumscribed, and often associated with inflammation and edema of the surrounding dermis and possible satellite lesions.

T3282

1072819-1072943

Epistemic_statement

denotes

Other clinical signs may occasionally result from the release of histamine or other vasoactive products from the mast cells.

T3283

1073058-1073209

Epistemic_statement

denotes

Histamine release stimulates the specific H2 gastric parietal cell receptors, resulting in increased acid secretion and perhaps local mucosal ischemia.

T3284

1073210-1073306

Epistemic_statement

denotes

Ulceration follows and may lead to fatal cytologic atypia with numerous bizarre mitotic figures.

T3285

1073467-1073581

Epistemic_statement

denotes

Mitotic activity is high, and phagocytosis may be evident, although it is much more profound in hemophagocytic HS.

T3286

1074391-1074457

Epistemic_statement

denotes

Lesions may wax and wane, but there is a poor long-term prognosis.

T3287

1074561-1074696

Epistemic_statement

denotes

Histologically, lesions consist of a diffuse dermal infiltrate of morphologically normal histiocytes that may extend into the subcutis.

T3288

1074697-1074728

Epistemic_statement

denotes

The epidermis may be ulcerated.

T3289

1075031-1075101

Epistemic_statement

denotes

Congenital histiocytosis is a very rare condition of neonatal piglets.

T3290

1075102-1075177

Epistemic_statement

denotes

Multiple cutaneous macules, papules, and plaques may be widely distributed.

T3291

1075416-1075482

Epistemic_statement

denotes

A few lymphocytes, plasma cells, and eosinophils may be scattered.

T3292

1076461-1076537

Epistemic_statement

denotes

Additional studies have corroborated the importance of a MI in grading MCTs.

T3293

1076664-1076774

Epistemic_statement

denotes

High proliferation indices (Ki-67, AgNOR) have been associated with a worse prognosis and poor survival times.

T3294

1076775-1076890

Epistemic_statement

denotes

The mast/stem cell growth factor receptor (protooncogene c-kit, CD117) appears to be involved in MCT tumorigenesis.

T3295

1076950-1077073

Epistemic_statement

denotes

Hypotensive shock from massive synchronous degranulation, as may occur with cryosurgery, is a rarely reported complication.

T3296

1078140-1078259

Epistemic_statement

denotes

The mitotic index (MI) appears to be a distinct The tumor is not encapsulated and is most often confined to the dermis.

T3297

1078260-1078317

Epistemic_statement

denotes

Collagen degeneration and stromal proliferation are rare.

T3298

1078546-1078651

Epistemic_statement

denotes

The tumor mast cells resemble histiocytes, and the lesion may be mistaken for granulomatous inflammation.

T3299

1078652-1078703

Epistemic_statement

denotes

Toluidine blue or Giemsa staining may be equivocal.

T3300

1079164-1079221

Epistemic_statement

denotes

The tumors may be hyperpigmented, alopecic, or ulcerated.

T3301

1079333-1079512

Epistemic_statement

denotes

Although in some respects resembling such lesions as cutaneous onchocerciasis, habronemiasis, or eosinophilic granulomas, none of these 3 is characterized by sheets of mast cells.

T3302

1079776-1079913

Epistemic_statement

denotes

In pigs, mast cell nodules have been described as tumors and as multifocal inflammatory aggregates, perhaps in response to Eperythrozoon.

T3303

1080056-1080240

Epistemic_statement

denotes

In cattle, scant data suggest that the cutaneous tumors are usually multiple and are associated with visceral mast cell aggregates, although purely cutaneous tumors have been reported.

T3304

1080566-1080619

Epistemic_statement

denotes

Cattle of any age, including calves, may be affected.

T3305

1081182-1081284

Epistemic_statement

denotes

Activating mutations in KIT as well as aberrant c-kit expression has been demonstrated in canine MCTs.

T3306

1081748-1081870

Epistemic_statement

denotes

Tumors with mutations in exon 8 or 11 have an increased likelihood of therapeutic success with tyrosine kinase inhibitors.

T3307

1082114-1082236

Epistemic_statement

denotes

Increased cytoplasmic staining is associated with increased rate of local recurrence and decreased survival time (see Fig.

T3308

1082349-1082515

Epistemic_statement

denotes

The surgical guidelines for MCTs suggest that these tumors be resected with surgical margins of 2-3 cm laterally and one tissue plane in depth to minimize recurrence.

T3309

1082516-1082770

Epistemic_statement

denotes

Wide margins are probably not needed for low-grade MCTs, In one study, 29% (15/51) of low-grade tumors had a histologic margin of 3 mm or less, and only 4% (2/51) recurred locally; 36% of high-grade tumors with complete surgical margins recurred locally.

T3310

1083027-1083215

Epistemic_statement

denotes

The metastatic potential of feline cutaneous MCTs is very low (~5%), and those destined for behavioral malignancy are easily detected by anisocytosis, hyperchromasia, and mitotic activity.

T3311

1083216-1083278

Epistemic_statement

denotes

An MI of >5 has been shown to negatively affect survival time.

T3312

1083279-1083430

Epistemic_statement

denotes

Apparent recurrence at the surgical site or elsewhere in the skin is seen in 25-50% of cases, but most of these probably represent multicentric origin.

T3313

1083624-1083766

Epistemic_statement

denotes

Mast cell tumors in cats appear as one or several firm, raised pink, alopecic papules ranging in size from millimeters to several centimeters.

T3314

1083767-1083895

Epistemic_statement

denotes

Less commonly, the tumor appears as a poorly defined area of swelling resulting from an infiltrative rather than nodular lesion.

T3315

1084025-1084207

Epistemic_statement

denotes

Histologically, the cells are usually extraordinarily uniform, polygonal to round, and grow in a diffuse sheet interrupted only by small clusters of lymphocytes and rare eosinophils.

T3316

1084411-1084556

Epistemic_statement

denotes

Even with metachromatic stains, such as Giemsa or toluidine blue, cytoplasmic granules may stain poorly, yet ultrastructurally they are abundant.

T3317

1084811-1085027

Epistemic_statement

denotes

CTCL frequently causes ulcers, and verification of the epitheliotropic nature of the neoplasm can be difficult; however, a neoplastic lymphocytic component that abuts the ulcerated epidermis suggests epidermotropism.

T3318

1085981-1086239

Epistemic_statement

denotes

Because the neoplastic population is often the minority population, the mitotic index should be evaluated carefully, taking into account the fact that the majority population is non-neoplastic small T lymphocytes with normal morphology and low mitotic index.

T3319

1086357-1086479

Epistemic_statement

denotes

The mixed nature of the population can lead to this tumor being mistaken for inflammation, or a neoplasm of T lymphocytes.

T3320

1086480-1086663

Epistemic_statement

denotes

T-cell-rich B-cell lymphomas in the horse appear to be histologically the same as the neoplasm referred to in the older literature as equine cutaneous histiolymphocytic lymphosarcoma.

T3321

1086664-1086858

Epistemic_statement

denotes

Angiocentric lymphoma (lymphomatoid granulomatosis) in the skin is usually a cutaneous manifestation of pulmonary lymphoma; however, it is thought to occur rarely as a primary cutaneous disease.

T3322

1086859-1086967

Epistemic_statement

denotes

Although well described in humans, this form of lymphoma has been reported infrequently in domestic animals.

T3323

1087251-1087389

Epistemic_statement

denotes

The neoplastic cells are medium- to large-sized lymphoid cells that can have a histiocytic appearance, with a cleaved or reniform nucleus.

T3324

1087390-1087501

Epistemic_statement

denotes

Inflammatory cells such as eosinophils, plasma cells, and small lymphocytes may accompany the neoplastic cells.

T3325

1087742-1087842

Epistemic_statement

denotes

The angiodestructive nature of the neoplasm can result in multifocal necrotic or infarctive lesions.

T3326

1088130-1088302

Epistemic_statement

denotes

This condition is rare in humans and was originally thought to be a proliferation of endothelial cells, which lead to the original name of malignant angioendotheliomatosis.

T3327

1088303-1088362

Epistemic_statement

denotes

At present, it has been reported rarely in the dog and cat.

T3328

1088363-1088547

Epistemic_statement

denotes

Clinically, the skin lesions appear as plaques and nodules, and histologically vessels in the dermis and subcutis are partially or completely filled with large atypical lymphoid cells.

T3329

1088548-1088702

Epistemic_statement

denotes

In humans, the intravascular neoplastic cells are of B-lymphocyte origin; however, in dogs, the majority of cases so far have been of T-lymphocyte origin.

T3330

1089123-1089268

Epistemic_statement

denotes

Pseudolymphomas in humans can be due to many antigenic stimuli, such as drug eruptions, arthropod or tick-bite reactions, and contact dermatitis.

T3331

1089448-1089556

Epistemic_statement

denotes

Differentiation between benign inflammatory lesions and early cutaneous lymphoma can be extremely difficult.

T3332

1089557-1089729

Epistemic_statement

denotes

Although immunophenotyping can distinguish between T-cell and B-cell lymphomas, methods to distinguish between recognized in humans and has been reported rarely in the dog.

T3333

1089888-1090009

Epistemic_statement

denotes

This may represent an early form of CTCL, as it is unclear if there is a true difference in clinical behavior in the dog.

T3334

1090010-1090121

Epistemic_statement

denotes

In cats, cutaneous epitheliotropic lymphoma is very rare and tends to be a more challenging clinical diagnosis.

T3335

1090217-1090272

Epistemic_statement

denotes

Adnexal involvement may be less common than in the dog.

T3336

1090511-1090611

Epistemic_statement

denotes

The majority of the lesions appear as solitary areas of alopecia with scaling, erythema, and ulcers.

T3337

1090612-1090741

Epistemic_statement

denotes

Skin lesions are frequently located on the lateral thorax but may also be found on any region of haired skin or the nasal planum.

T3338

1091011-1091220

Epistemic_statement

denotes

Although the disease tends to be very slowly progressive, infiltration of internal organs by lymphocytes may occur along with clinical signs of systemic disease, such as lethargy, inappetence, and weight loss.

T3339

1091705-1091880

Epistemic_statement

denotes

Inflamed nonepitheliotropic T-cell lymphoma is form of cutaneous lymphoma in dogs that can be difficult to differentiate morphologically from cutaneous reactive histiocytosis.

T3340

1091977-1092071

Epistemic_statement

denotes

Lesions may be found on the mucocutaneous junctions of the face, extremities, neck, and trunk.

T3341

1092586-1092670

Epistemic_statement

denotes

Although the clinical course is variable, the median survival time is only 9 months.

T3342

1092921-1092995

Epistemic_statement

denotes

In the horse, it appears to be the most common form of cutaneous lymphoma.

T3343

1093398-1093514

Epistemic_statement

denotes

Mammary gland carcinomas in the cat may also metastasize to the ventral abdominal tissues by using similar pathways.

T3344

1093515-1093595

Epistemic_statement

denotes

Primary epitrichial gland carcinoma of the skin may be difficult to distinguish.

T3345

1093791-1093953

Epistemic_statement

denotes

Cutaneous metastasis of internal tumors is rare in cats and have been reported in association with mammary adenocarcinoma and digestive and respiratory carcinoma.

T3346

1094191-1094244

Epistemic_statement

denotes

Clinically, the lesions are suggestive of paronychia.

T3347

1094382-1094465

Epistemic_statement

denotes

Bony lysis of the third phalanx may be evident radiographically and histologically.

T3348

1094644-1094810

Epistemic_statement

denotes

Abdominal surgeries to remove transitional cell, colonic, or prostatic carcinomas have the potential for implantation of tumor cells in the skin at the surgical site.

T3349

1094811-1094883

Epistemic_statement

denotes

Tumor cells may also reach the skin via retrograde lymphatic metastasis.

T3350

1094971-1095078

Epistemic_statement

denotes

Tumors metastatic to the skin A variety of tumors can metastasize to the skin, but the process is uncommon.

T3351

1095079-1095160

Epistemic_statement

denotes

Cutaneous metastasis may be the first sign of an undiagnosed visceral malignancy.

T3352

1095996-1096199

Epistemic_statement

denotes

Cutaneous metastasis of transitional cell carcinoma is uncommon in dogs; however, it has been reported to occur after previous abdominal surgery for TCC and to occur through lymphatics and blood vessels.

T3353

1096200-1096335

Epistemic_statement

denotes

Transepidermal metastasis has been suggested, because in most cases, cutaneous lesions are in close proximity to the vulva and prepuce.

T3354

1096336-1096416

Epistemic_statement

denotes

Some believe neoplastic cells from the urine may seed eroded urine scalded skin.

T3355

1096417-1096606

Epistemic_statement

denotes

Cutaneous lesions appear as plaques, papules, and nodules and most often occur in the perineal, inguinal, or ventral abdominal dermis or subcutis in dogs with or without history of surgery.

T3356

1096671-1096740

Epistemic_statement

denotes

Visceral hemangiosarcomas may metastasize to the subcutis in the dog.

T3357

1096741-1096865

Epistemic_statement

denotes

Subcutaneous hemangiosarcomas, particularly if multiple, should prompt the clinician to search for a primary visceral tumor.

T3358

1096866-1096932

Epistemic_statement

denotes

Metastatic tumors may be fairly well differentiated or anaplastic.

T3359

1096933-1097018

Epistemic_statement

denotes

Mammary gland carcinomas in the dog may metastasize to the dermis of the inner thigh.

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