My dog isn't eating his food but is drinking water. What's wrong?

A dog may stop eating for a wide variety of reasons, some of which are due to medical conditions and others that may be more behavioral. Medical problems such as gastrointestinal viruses, intestinal obstructions, parasites, or kidney disease, among other conditions, can lead to this problem. Other dogs may become disinterested in their food and may prefer a different flavor of food, or the taste of the food may have changed due to the container in which it is stored.

If your dog is still active and playful, you can try to tempt them to eat with a bland diet of boiled white meat chicken and white rice for a few days before gradually transitioning back to either their original diet or to a new food. (Any time you change diets, be sure to do so gradually by mixing the old and new foods together over 5-7 days.) If this is unsuccessful or if your dog is lethargic, vomiting, or having diarrhea, a visit to the veterinarian is in order. The veterinarian will be able to perform a physical exam as well as any necessary diagnostic tests to try to get to the bottom of this issue so that proper treatment can be started.