My 2 yr old Yorkie is the pickiest eater, he will eat Puperonis. I have tried just about every dog food on the market, dry & wet, on occasion he will eat a helping like Ceasers or nibble on a dry food. But then he will just ignore it to the point of throwing up from not eating. Feeling sorry for him I will resort to human food. Chicken & rice & then he gets diarea, then I swear nothing but dog food from now on then he won't eat It's a vicous cycle. Any ideas on what to try next?