If your dog has been vomiting for more than two days, does not drink water or eat food and is very sleepy get him to a vet. In the meantime, he might have eaten something bad. Give him pedialyte-unflavored to help with the dehydration. If diarhhea is involved get to the vet if this problem continues for more than 48 hours! Keep him hydrated with pedialyte for now to see if whatever he may have eaten passes through.