Parvovirus in Dogs
A highly contagious viral disease of the GI tract, most common in unvaccinated or incompletely vaccinated puppies between 6 weeks and 6 months old.
Overview
Canine parvovirus (CPV-2) attacks rapidly dividing cells, primarily in the intestinal lining and bone marrow, and in very young puppies can also affect the heart muscle. It spreads through the fecal-oral route and is extremely hardy in the environment, remaining infectious on surfaces for months to over a year. Risk is highest in puppies that are unvaccinated, under-vaccinated, or between doses in the vaccine series.
Clinical signs
- Lethargy and anorexia
- Vomiting, often persistent
- Profuse diarrhea, frequently hemorrhagic and foul-smelling
- Fever or, in severe cases, hypothermia
- Dehydration and abdominal pain
Diagnosis
- In-clinic fecal ELISA antigen test (SNAP test) as first-line screening
- CBC frequently shows leukopenia/neutropenia, which supports the diagnosis
- PCR testing for confirmation in ambiguous or recently-vaccinated cases
Treatment
- IV fluid therapy to correct dehydration and electrolyte imbalances
- Antiemetics to control vomiting
- Broad-spectrum antibiotics, since the compromised GI barrier carries a real risk of secondary bacterial translocation and sepsis
- Early enteral nutrition as soon as it is tolerated
- Hospitalization/inpatient care for moderate-to-severe cases; select stable cases may be managed with outpatient protocols
Prognosis
With aggressive supportive care, reported survival rates are generally in the 80-95% range. Without treatment, mortality is very high. Prognosis is worse in very young puppies and in cases presenting with marked leukopenia or septic complications.
This page is general reference information for educational purposes. It is not a substitute for an individual clinical assessment, current formulary guidance, or the judgment of a licensed veterinarian treating a specific patient.
Frequently asked questions
How long is a dog contagious with parvo?
Dogs typically shed the virus for up to two weeks after clinical recovery, and sometimes longer. Your veterinarian can advise when it is safe to reintroduce your dog to other unvaccinated animals.
Can a fully vaccinated dog still get parvo?
It is uncommon but possible, particularly if the vaccine series was not completed on schedule or in dogs with an inadequate immune response. Completing the full puppy series and boosters as recommended provides the best protection.