I rescued a bulldog that was on his way to the pound... I have noticed that he drinks water non stop, and large amounts of water. When I take it away from him he cries. I got him to eat last night because I put boiled chicken in his food. Yesterday and today he threw up, and the majority of it was water. When he sleeps and when he is relaxed he shakes like crazy. I took him to the vet for a check up and they did a diabetes test on him and it came back normal. Any advice, or has anyone experienced this?