His stomach may just hurt too much at this point for him to want to put anything in it. The vet can give him an anti-nausea shot if this is the case. Let us know what happens!
Thanks deadgamegrrl! I forgot to add that he was drinking a lot of water before he stopped.
If your dog has not drunk anything for over 24 hours, I would get to a vet asap. He could be seriously dehydrated and need IV or subcutaneous fluids at the very least. If he was only vomiting I would try a 24 hour fast and then small amounts of boiled chicken and rice, but at his age and being unable to hold down fluids I think you need to see the vet. Good luck.