When a dog only drinks water but does not eat, it may be that the dog is a picky eater. You can try changing to some more palatable dog food, or you can add some canned food to the dog food and try to see if the dog eats it. If your dog is neither eating nor in a good mental state, it may be a loss of appetite caused by a disease. In this case, you need to take it to the hospital for a doctor's examination.

We should check whether there is an increase in body temperature and check whether the dog has been vaccinated. If not vaccinated, parvovirus and canine distemper must be suspected. If deworming has not occurred, a serious parasitic infection needs to be suspected.