Food allergy in the cat: a diagnosis by elimination

Food allergy is recognized as a cause of non-seasonal dermatologic disease and pruritus in cats, though its exact prevalence remains unknown. Feline food allergy can also be associated with gastrointestinal, neurologic, respiratory and behavioral components.

There are no breed, sex or age predispositions for developing food allergy, though there is some evidence that the Siamese and its crosses may be at increased risk.

Food allergy cannot be diagnosed simply on the basis of the distribution of pruritus, and many of the dermatologic reaction patterns observed in affected cats, such as miliary dermatitis, eosinophilic granuloma complex and alopecia, may be seen in cats with flea allergy and atopy; in some cases, cats may have concurrent allergic conditions. The only way to definitively diagnose food allergy is to identify a causative food component through a food elimination trial. However, palatability and client compliance can each be a problem; specifically, many owners are unwilling to perform a provocation challenge, which is required to confirm a suspected food allergy. For cats in which the existence of a food allergy is confirmed, a suitable maintenance diet then needs to be fed for the remainder of the patient's life.

Recent literature has revealed that there is marked variability in the clinical picture, response to treatment and outcome in food-allergic cats. This article reviews published literature and highlights clinically relevant observations pertinent to feline food allergy.