If your dog eats chocolate it is not necessarily a medical disaster. A dog has to eat a fairly large amount for it to effect him, basically 1 ounce of chocolate per pound of dog. There is much you can do once he has eaten the chocolate except to watch for symptoms. Symptoms include Hyper excitability or irratability, restlessness, increased urination, muscle tremos, vomiting and diarrhea. If these symptoms appear get your dog to the Vet.