Canine parvovirus (CPV) or "parvo" is a contagious, viral disease that most commonly affects puppies and young dogs that are not adequately vaccinated. The virus is shed in large amounts in the stool of infected individuals and survives in the environment for long periods of time.




Dogs that have been infected with parvovirus typically stop eating, are lethargic, vomit, and have diarrhea, which may contain blood. Because the virus prevents the immune system from functioning properly, secondary bacterial infections (e.g., pneumonia) can develop in severe cases. A veterinarian will diagnose parvovirus and rule out other diseases that can cause similar symptoms based on a pet's history, clinical signs, physical exam, fecal examinations, blood work, and laboratory testing that can identify the virus in a stool sample. X-rays may be necessary if other abdominal disorders or pneumonia are suspected.




Therapy for parvovirus depends on the severity of the infection but intravenous fluid therapy, antibiotics, and medications to prevent nausea and vomiting are commonly used. Plasma transfusions may be necessary in severe cases, and some dogs do still die despite aggressive treatment. Many animals need to be hospitalized for several days until they are able to hold down food and water and leave the veterinary clinic to go home and finish their treatment. Individuals with parvovirus can easily transmit the disease to other, unvaccinated dogs and sometimes to cats and so should be isolated. Thorough disinfection of contaminated environments will also help prevent the spread of the virus. Vaccination on an appropriate schedule is extremely effective in preventing this potentially fatal disease.


Written by: Jennifer Coates, DVM
Last reviewed: October 2, 2008