Adverse Food Reactions in Dogs and Cats.

Adverse food reactions (AFRs) are a frequent cause of chronic pruritus and gastrointestinal disease in dogs and cats. They include immunologic (allergic) and nonimmunologic reactions, with diagnosis remaining challenging due to nonspecific clinical signs. Current diagnostic tests (serum immunoglobulin E/immunoglobulin G, saliva, and hair) lack reliability, and elimination diet trials with dietary provocation remain the gold standard. Hydrolyzed diets are practical first-line options, while elemental diets may further improve diagnostic accuracy in the future. Advances in understanding T-cell-mediated mechanisms highlight the potential of lymphocyte proliferation assays, although further validation is required before clinical implementation.