I have a cat that's allergic to most cat foods. I feed her Blue Wilderness grain FREE cat food, dry or canned. I would try out some of the completely grain free higher quality types, like Wellness CORE or Blue Wilderness. Also, if it is a grass or other seasonal outside allergy, you can try bathing more frequently. My parents' last dog ad seasonal allergies and washing him with my handmade cold process (NOT glycerin) soap really helped his itchy rashiness quite a bit.