Canine parvovirus is a highly contagious viral disease that affects dogs. It was first recognized in 1978 and spread worldwide within two years. There are three strains of the virus. The virus enters dogs orally and attacks rapidly dividing cells in the intestines, preventing absorption of food and liquids. Symptoms include lethargy, loss of appetite, vomiting, and bloody diarrhea. Puppies and young dogs are most at risk. Treatment requires hospitalization, intravenous fluids, antibiotics, and supportive care for 5-7 days. Prevention focuses on vaccination, sanitation, and isolation of infected dogs.