A. Etiology is a type I hypersensitivity predominantly but a type III and type IV reaction may also occur. Animals are predisposed
to develop food allergy through undefined genetic factors.
B. Historical findings
1. No sex predisposition exists
2. Breed predisposition may include Labrador retrievers, Shar Pei, English Springer Spaniels, Miniature Schnauzers, Cocker
Spaniels, Collies, and Golden retrievers, but any dog may develop food allergy.
3. Primary complaint is pruritus that is non-seasonal.
4. Age of onset is usually less than 3 years but may occur later in life or at any age.
5. Problem persists regardless of the commercial brand of food fed because of the similarity of ingredients. Onset of
symptoms is usually not associated with a recent dietary change. Many dogs with food allergies have been on the diet that
they are allergic to for 2 or more years before showing clinical signs.
C. Clinical findings
1. Chief complaint is pruritus
a. Dog distribution includes the face, feet, forelegs, axilla, ears, and sometimes inguinal or perianal regions
(or any combination)
b. Cat distribution includes the face and neck, especially the pre-aural region between the lateral canthus of the
eye and the base of the pinna. Any type of eosinophillic granuloma or miliary dermatitis may also be present.
2. Urticaria may be present (dogs)
3. Concurrent GI symptoms are uncommon but can occur.
4. Seizures are occasionally associated with food allergy
5. Secondary pyoderma or otitis is common in dogs.
D. Differential diagnoses
1. Non-seasonal atopy
3. Flea allergy (non seasonal)
4. Allergic contact dermatitis
5. Malassezia dermatitis or pruritic pyoderma