Is there a medical reason you switched your cat to canned food? If not, I would put out your kitty's favorite dry food and leave it out so he can feed freely throughout the day. My cat lived to be nineteen, and he ate dry food (Purina One) right up to the end when he started refusing to eat at all. Dry food helps to keep an animal's teeth clean and healthy. My old cat had every one of his teeth on the day he died, and he never suffered with any gum diseases. I hope your kitty feels better soon.