health
Parvovirus (canine CPV-2)
Classic presentation
- Profuse vomiting and severe, often bloody diarrhea, typically a distinctive metallic odor.
- Profound lethargy, dehydration, hypothermia or fever.
- Marked leukopenia on bloodwork (the bone marrow suppression component).
- Onset 5–10 days after exposure; most cases are in puppies 6 weeks to 6 months old.
Diagnosis is typically a fecal antigen test (ELISA), a positive test in a sick, unvaccinated puppy with consistent signs is the standard.
Treatment is supportive and intensive
There is no specific antiviral. Treatment is aggressive hospitalization: IV fluids and electrolytes, antiemetics (maropitant, ondansetron), broad-spectrum antibiotics for secondary bacterial translocation, parenteral or early enteral nutrition, and pain control. Survival rates with appropriate hospitalization exceed 80%; without hospitalization, mortality is high. Outpatient protocols (subcutaneous fluids, oral medications) exist and have a published evidence base, but should be used only when in-hospital care is genuinely inaccessible.
Prevention and environmental persistence
Vaccination is the prevention. CPV-2 is part of the canine core vaccine series, typically administered at 6–8 weeks, 10–12 weeks, and 14–16 weeks, with a final dose at or after 16 weeks because maternal antibody interference is common before that age. Until the series is complete, keep puppies away from unknown dogs and public ground that may be contaminated.
The virus is non-enveloped and extraordinarily stable in the environment, months to over a year on surfaces, resistant to most common disinfectants. Sodium hypochlorite (household bleach) at a 1:30 dilution is the standard disinfectant; quaternary ammonium products do not reliably inactivate it.
Why it matters
Parvo is preventable. Every parvo case we hear about traces back to either a missed vaccine, an incomplete series exposed too early, or environmental contamination from another unvaccinated dog. The vaccine works; the breakdown is almost always in human decisions, not viral mutation.
Frequently asked questions
- Can a vaccinated dog get parvo?
- Breakthrough infections happen but are rare. Most breakthrough cases trace to incomplete puppy series, maternal antibody interference, or immunosuppression. A dog who has completed the full series and received its 1-year booster is well protected.
- Is parvo contagious to humans or cats?
- Canine parvovirus is not contagious to humans. A distinct parvovirus (FPV, feline panleukopenia) affects cats; the canine and feline viruses are closely related but the standard core vaccines for each species cover them appropriately.