FOOD ALLERGy IN THE HORSE: A DERMATOLOGIST’S VIEW

Food allergy is an uncommon and poorly understood disease in the horse. Symptoms can be gastrointestinal, dermatologic, or both. The terminology itself is confusing. The term food allergy implies an immunologic reaction to an ingested substance. Not all food allergies are truly allergic in nature. A better term for the condition would be “adverse reactions to food.” This designation includes immunologic and nonimmunologic reactions to food substances. Nonimmunologic food sensitivities include metabolic, pharmacologic, and idiosyncratic reactions. An example of this would be pruritus resulting from the histamine content of a food (e.g., mackerel or tuna), instead of from an allergic reaction to the food itself. Fortunately, clinical symptoms and treatment of immunologic and nonimmunologic food reactions are identical. Therefore, for the sake of simplicity, most clinicians use the term food allergy to indicate adverse reactions to food.