my 5 yr. old golden retriever has been losing a lot of weight. it started about 3 weeks ago when he didnt want to eat his dog food, i thought he was just being stuborn because when i put some table scraps in it he ate it. Then after about a week he began vomiting occasionally and had diarreah. after that he began eating very little and drinking alot of water. he has lost alot of weight now and is very moppey. i also have a black lab and he is not ill at all. what can this be and what can i do?
Optional Information: Age: 5; Male; Breed: golden retriever
Already Tried:
i have given him hamburger and rice a few times he eats a little and then doesnt want anymore, but he keeps it down.