For best results go to a board certified veterinary dermatologist. Food allergies are rare. Food sensitivities fluctuate.
More often than not environmental allergies are the culprit.
The only accurate test for that is intradermal skin testing. The most natural treatment for environmental allergies is allergen specific immunotherapy otherwise known as allergy shots or desensitization.
See my posts, example /forums/topic/hes-got-good-and-environmental-allergies/#post-113364
/forums/topic/hes-got-good-and-environmental-allergies/#post-113364
