You know what Gloria, Caro may be onto something. My kitty Mario got very ill at about age 7, and after many tests and $$$ (and he was so thin from vomiting and not eating) we figured out he has IBS and cannot eat chicken. Once we got him eating again (he subsisted on the calorie paste for a few days that I wiped on the roof of his mouth), we switched him to tuna and he has been fine ever since. It was such a stressful time. I think it's definitely worth changing his protein to check it out. My dogs all eat Wellness Lamb and Barley - it has some fish meal in it, no chicken protein but it does have some chicken fat. But there are lots of foods out there to check out. Hope he is feeling better.