I've admittedly had trouble totally weening mine off dry food entirely. One cat will only eat a small amount of canned at a time, even without access to any other food. The other cat will inhale any food he leaves behind so I have to supervise every meal. Well, there's only so many times a day that I can give him wet food and only so much of it that he'll eat, so we end up leaving a high protein dry food out for them as well. He is drinking a decent amount of water these days, too. It's not perfect, but it's arguably going to have to do. The vet is happy with his labs and appearance. Thankfully, our younger cat poses no problem. She lives for canned food.