Rosebud, I have dogs. I was told by my vet that puppies that age should be allowed to eat and drink as they wish. Just put dry food and water and let him make his own schedule to eat or drink. After he eats and drinks, take him outside so he can urinate and have BM. This stage in your dog's life is like infancy in humans. They love to sleep. So please leave him alone when he is sleeping. They need sleep to grow. No, you don't have to take the dog to the vet not unless you observe that he has diarrhea, vomiting, and lethargy. Observe him tomorrow. If he does not eat and drink all day long and he just sleeps and is not playful, then take him to the vet. I think by the way it sounds, there's nothing to worry about.