Parvo, canine corona virus, coccidia, etc. There are so many possibilities. I would take him to the vet asap and get your pup tested and treated. Some of these problems could kill your pup within 24 hours if not handled properly. Keep your pup hydrated if he is throwing up or having diarrhea and won't eat. Pedialyte, gatorade, water, etc. If he won't drink it, get a syringe without a needle and force him. Make sure his gums stay pink until you make it to the vet.