If your dog vomits and refuses to eat, you should check whether it has been vaccinated. If the dog has not been vaccinated, you must suspect the possibility of parvovirus and canine distemper. If you are vaccinated but not dewormed, you should suspect a parasitic infection. You should suspect the possibility of swallowing foreign objects, and recall carefully to rule out the possibility that the dog has swallowed toxic substances. Rule out whether there is vomiting caused by digestive system diseases.