If he is not sick anymore, maybe he is just tired of that food? I switched Uni's food soooooo many times. She would just stop eating it. I would have to beg her to eat, mix in canned, warm it in the microwave. When I switched foods, she would eat the new food, then get tired of it. Exactly when I would purchase a 2nd bag, like the next week she changed her mind and didn't like it anymore
Finally found Wellness and she loves it.