Please take your dog to a vet. Vomiting for more than a day is a good indication that there is a serious problem. If it was your child that was vomiting you wouldn't wait 3 days would you? There are many things that could cause these symptoms, all of which are serious. Parasites, Parvo and Foreign Body Obstruction (ate something he shouldn't have) are a few of the major things that could be going on. All of which a vet visit is NECESSARY.
FYI - the above post said that drinking lots of water and chicken broth helped other dogs fight off the parvo virus - it is incorrect. When a dog has parvo there is nothing you can do to fight the virus itself. (kinda similar to the human flu virus) Once a dog has parvo the best thing is to give them supportive care for dehydration and secondary infections to help prevent other problems from forming while THE DOG itself fights off the virus. You can also give medications to help stop the vomiting and diarrhea. I have been a veterinary technician for 5 years so I have had plenty of experience with parvo puppies. Please take your dog to a vet to find the cause of the vomiting and get him some help. Thank You.
FYI - the above post said that drinking lots of water and chicken broth helped other dogs fight off the parvo virus - it is incorrect. When a dog has parvo there is nothing you can do to fight the virus itself. (kinda similar to the human flu virus) Once a dog has parvo the best thing is to give them supportive care for dehydration and secondary infections to help prevent other problems from forming while THE DOG itself fights off the virus. You can also give medications to help stop the vomiting and diarrhea. I have been a veterinary technician for 5 years so I have had plenty of experience with parvo puppies. Please take your dog to a vet to find the cause of the vomiting and get him some help. Thank You.