Study Diets
Cats were randomized to be fed one of two commercial veterinary therapeutic dry gastrointestinal formulas, Diet A2 or Diet B.3 No additional foods or treats were permitted. All investigators and participants were masked to the identity of the diet. Study diets were re-packaged into white bags, sealed, and delivered directly to participating veterinary clinics by plant employees not participating in the study. Nutrient analysis (conducted internally at Iams Analytical Laboratory), caloric distribution, and ingredient composition is summarized in Table 1. Cats were fed according to each product’s feeding guidelines to maintain body weight.
Table 1  Nutrient analysis, caloric distribution, and ingredient composition of study diets fed to 28 cats with chronic gastroenteropathy.  Nutrient analysis conducted at the Iams Pet Care Analytical Lab; AF, as fed; NFE, nitrogen-free extract, determined as 100% − (% moisture + % protein + % fat + % ash + % crude fiber); ME, metabolizable energy.