Phosphorus is the third medicine to considering, especially if there is desire of cold water that he vomits so soon it comes to the stomach. This it is Phosphorus's symptom typical well and also of the canine parvovirosis in initial conditions(states). Phosphorus's depositions are abundant and watery, go out strongly.
Arsenicum's vomits can be of all the types, from water up to snot, bile or blood. Arsenicum's pains are intense. Veratrum since well they have advised him it is important to having in bill. It has an important characteristic, the collapse. Bluish skin, purple, cold and wrinkled. It is more indicated in final conditions(states) of the disease.
Luck.