Your dog may have food or environmental allergies, has contracted a virus, or has been infected with parasites. It is important that you see a qualified veterinarian immediately.
Check the following: The dog has gotten too hot, he has eaten vegetation that is new to the yard, he has possibly consumed a pesticide or insect killer.
He might have a virus similar to stomach flu. He could have eaten something toxic outside or in the garage. He may have eaten chocolate, also. Go to the vet.
