At the next regular feeding time, repeat the process. You aren't starving him. His fast is self-imposed, and he will eat the food you give him before he does any harm to himself. Once he does eat, keep to a regular pattern of feeding and don't give in-between meal handouts. In addition to a proper diet, it is very important to provide plenty of fresh water for your dog at all times.
Water comprises approximately two-thirds of a dog's total body weight.
Water is not stored in the body like some other nutrients, so it must constantly be replaced. It's always better to prevent a problem rather than treat one. So any basic health care plan for your dog should include regular visits to your veterinarian. Regular veterinary care will identify potential trouble areas and allow early treatment if it is needed. Your adult dog should have a thorough physical examination at least once a year.