If the cat requires more treatment, and antihistamines are not effective, immunotherapy will be started based on intradermal or in vitro test results. Side effects of antihistamines include sedation, hyperexcitability, excessive salivation due to the bitter taste of the medication, teratogenicity and constipation. Conversely, fatty acids can cause soft stools or diarrhea. Food allergy Food allergy should be considered in cats with nonseasonal pruritus. Some food allergic cats will be somewhat steroid responsive, so do not rule out food allergy based on steroid responsiveness alone.
Food allergy can occur at any age and affect any area of the body.
Clinically, lesions may be confined to excoriations of the head and neck but eosinophilic granuloma complex lesions, bilateral symmetrical alopecia due to self-induced grooming, recurrent otitis and miliary dermatitis can be present. Since there is no valid skin or in vitro testing for food allergy, a hypoallergenic diet trial remains the most accurate way to diagnose food allergy. Simply changing from one brand of commercial food to another or one that contains lamb and rice is not adequate. Be careful when changing diets in cats because some can be very picky eaters and refuse to eat. It is also helpful to not separate the new hypoallergenic diet from the cat's current diet when introducing the new food.