There’s nothing like the excitement and happiness of bringing a new puppy home. But that joy can quickly turn to worry if the puppy starts feeling unwell and the veterinarian mentions “parvo.” Learn more about the symptoms and treatment of canine parvovirus and how to help protect puppies and adult dogs from this highly contagious virus.
What Is Parvo (Canine Parvovirus)?
The full name for parvo is canine parvovirus type 2 (CPV-2). It is a highly contagious virus that affects dogs, especially puppies and dogs that are unvaccinated or not fully vaccinated. The virus targets rapidly dividing cells, particularly those in the intestinal tract, bone marrow and lymphoid tissues. Damage to the intestinal lining interferes with normal absorption of nutrients and fluids, which can quickly lead to severe dehydration. At the same time, suppression of the bone marrow weakens the immune system and increases the risk of serious secondary bacterial infections. Canine parvovirus is related to feline panleukopenia virus, which causes similar symptoms and severe illness in cats. Certain breeds tend to be more vulnerable to parvo, including Doberman pinschers, German shepherds, Rottweilers, Labrador retrievers and bull terriers.
How Do Dogs Get Parvo?
Canine parvovirus infection occurs when healthy dogs have direct or indirect contact with the contaminated feces (poop) of dogs infected with the virus. Wild canines (wolves, foxes, coyotes), stray dogs and occasionally other animals such as raccoons and skunks can all spread the virus to domestic dogs. One of the reasons puppy parents need to be aware of the risks of parvo is because an infected dog can shed large amounts of virus in its poop even before signs of illness are seen. So a puppy friend may seem healthy and safe to play with, but they may actually be transmitting this highly contagious disease to your pup.
Infected dogs shed the virus in feces within 4–5 days following exposure, during illness, and for approximately 10 days after recovery. Consequently, kennels, food and water dishes, collars and leashes, and the hands and clothing of people who handle infected dogs can be easily contaminated with the virus.
The virus is extremely hardy and can survive in the environment for up to two years under the right conditions. Most disinfecting household cleaners will not kill parvovirus, making it tough to disinfect surfaces once they’re contaminated. And given that places such as dog parks, pet stores, lawns and even homes aren’t cleaned with disinfecting products regularly, a dog can be exposed to parvovirus when it’s least expected.
What Are Parvo Symptoms?
Unfortunately, some of the signs of parvo, at least at first, can be confused with simple digestive upset. This often causes owners to postpone treatment until their puppies or dogs are severely dehydrated. The delay can also expose other dogs in the home to the virus.
Early symptoms usually include lethargy (tiredness), loss of appetite, abdominal pain and bloating, fever or abnormally low body temperature, followed by severe vomiting and profuse, foul-smelling, often bloody, diarrhea. Persistent vomiting and severe diarrhea can cause rapid dehydration, especially in young puppies. These symptoms can be a sign of a severe infection and need immediate treatment.
Due to the impact on white blood cells, a sick dog’s weakened immune system makes it harder to fight secondary infections. Without prompt veterinary attention after clinical signs begin, the dog’s condition can become life-threatening within a short period of time.
How Is Parvo Diagnosed?
Any puppy or unvaccinated dog with signs of vomiting and diarrhea should be tested for parvovirus. A veterinary team will most commonly diagnose parvo using a rapid fecal ELISA “snap” test, which can detect viral antigens in their poop in as little as 15 minutes. Veterinarians often support this result with a complete blood count (CBC), looking for leukopenia, which is a decreased white blood cell count.
Is There a Parvo Treatment?
Canine parvovirus monoclonal antibody (CPMA) is a one-dose treatment option for parvovirus in dogs 8 weeks of age and older. But early treatment is critical; it should be given at the first signs of the virus. The CPMA is a synthetic antibody that mimics a dog’s own antibodies and selectively binds to the parvovirus, preventing it from entering and destroying intestinal cells. While it can neutralize the virus, it can’t reverse damage already done to the cells. A single dose of the treatment is given intravenously and has been shown to reduce disease severity and improve survival when administered early alongside supportive care.
Traditional treatment focuses on supportive care, which includes intravenous fluids, antibiotics to treat or prevent secondary bacterial infections and medications to manage vomiting and diarrhea. Supportive care aims to correct severe dehydration and electrolyte imbalances caused by vomiting and diarrhea while also controlling nausea and pain. In extreme cases, blood transfusions may also be administered to help increase low blood cell counts. In some severe cases, hospitalization for intensive care may be necessary. Treatment can be very expensive, and while up to 85 to 90 percent of treated dogs can survive, some dogs may still die despite aggressive treatment.
Can Older Dogs Get Parvo?
Yes, adult dogs can get parvo, but it’s much less common than in puppies. Parvo tends to affect unvaccinated puppies and adolescent dogs the hardest because their immune systems aren’t fully developed. However, an older dog can still become infected if they were never vaccinated, didn’t complete their vaccine series or have a compromised immunity due to illness or age.
Can Parvo Be Prevented?
Because parvo can have such devastating consequences, and it’s still quite common, veterinarians consider vaccination against parvovirus to be an essential part of preventive health care. Other ways to prevent parvo transmission include good hygiene and avoiding high-risk areas where infected dogs may be (e.g., dog park, pet store, groomers) until your dog is fully vaccinated.
Many vaccines are now available to veterinarians, and often a single dose can be given to protect against several common diseases, including parvovirus. Typically, the first parvovirus vaccine, which is a combination vaccine, is recommended at 6–8 weeks of age, followed by boosters. Getting vaccinations will always have benefits for your pets. You’ll want to discuss your dog’s vaccination needs with your vet, who will develop a preventive health care plan based on your dog’s life stage, lifestyle, risk of exposure and underlying health conditions.
