He is not on any meds. The dr. says all blood work is fine. He is not doing good! Loosing weight quick, throwing up continuously and diareha. He won't stop drinking water! He hasn't been on our counters for a few years but he is wanting on it now to drink water. He is continuously hungry and wants to eat all the time. There are times that he seems disoriented.He sleeps a lot. I think he is loosing muscle mass also. I am going to the vet again tomorrow. What is the best food to feed him?