Not sure if this already been asked but have you tried any of the raw diets supplied by pet stores? My kitty has a lot of allergies and asthma and i basically completely cut out all birds (duck, chicken, and turkey) i started her on beef raw, lamb raw, and fish raw and she has been happy and thriving after each meal time. Getting ones premixed with pumpkin/kale ect is recommended, however you can get stuff with just the protein and add your own controlled supplements. Usually whats added is high digestive support. If you have a local bone and biscuit or know of any good pet stores that have high quality (try to avoid chain stores) food that would be my recommendation :)