| Although most human food is Ok for dogs, there are a few things, chocolate, grapes, raisins, onions, Xylitol, and others that can kill a dog. Unless you have fed him some of those, I would give him a day or 2 to recover. Maybe let him eat some grass. It may bring up whatever is bothering him. Any sudden changes of diet can upset a dog's digestion. If he doesn't start eating again in a day or 2, better call the vet. Certainly before the weekend.
When he is ready to eat again, offer him some dry dog food. It would be best to stick to what the former owners were feeding him if it was a dry dog chow passing AAFCO tests. An occasional little tidbit from the table put in his dish is OK, but for such a small dog, it must be very little. The easiest way to give a dog a healthy diet is to make sure almost all of its calories come from a commercial dog chow.
It is very easy to over feed small dogs. I couldn't tell too much by the picture. Your dog definitely should be narrower at the waist than the hips and chest. You should be able to easily feel the ribs, but not see them. Each dog is different. Standard recommendations are a good place to start, but each dog must have its food adjusted to its individual needs.
Thank you for giving him a home. I am very upset about all the nice dogs slaughtered at the shelters for lack of homes. |