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Everything You Need to Know About Parvo in Dogs

The potentially deadly virus can be prevented with one simple step.

by Abbie Deleers, LVT
June 8, 2021
Cavalier King Charles spaniel puppy running in a garden
Waldemar Dąbrow/Adobe Stock

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Here is yet another reason to make sure your dog is up-to-date on their vaccinations: They’ll avoid a potentially deadly virus known as canine parvovirus (CPV) or “parvo.” Most commonly found in puppies who haven’t been vaccinated yet, parvo messes with your dog’s gastrointestinal tract and can lead to dangerous levels of dehydration and malnutrition. Here’s everything you need to know, including the symptoms to look out for and the preventative steps you can take.

What is Parvo in Dogs?

Canine Parvovirus (CPV), often referred to as “parvo,” is a highly contagious and potentially deadly virus that affects dogs’ intestinal tract. Not only does parvo have a high mortality rate if left untreated: It can survive in the environment for months, or even years, in the right conditions.

While any dog may potentially contract parvo, it is most likely to affect dogs with weak immune systems, including puppies and unvaccinated dogs. Puppies are especially vulnerable to parvo infections during the gap between immunity from their mother’s milk and when they are fully vaccinated at 16 weeks old. Dogs with existing autoimmune deficiencies are also at greater risk.

How is Parvo in Dogs Transmitted?

The parvovirus enters the body through contact with the mucus membranes, then spreads in the lymphatic system and bloodstream. An infected dog sheds the parvovirus through feces, so transmission of parvo can occur when other dogs come in contact with those feces directly (via their nose or mouth), or indirectly (by touching contaminated items).

The virus can also be passed along on multiple surfaces, including fur, food bowls, toys, kennels and bedding, and dirt and grass contaminated by infected feces. A dog with parvo can start shedding the virus as soon as four days after exposure, often before symptoms begin to manifest and before they are known to be infected.

What Are the Symptoms of Parvo in Dogs?

A parvo infection decreases the ability of the gastrointestinal tract to absorb vital nutrients and water. This can lead to dangerous levels of dehydration and malnutrition. Common signs and symptoms of parvo include:

  • Diarrhea, often bloody

  • Vomiting

  • Hypothermia (below-normal temperature)

  • Lethargy

  • Weight loss

  • Lack of appetite

  • Bloated and/or painful abdomen

If you observe any of these symptoms in your dog, it’s crucial that you take them to the vet as soon as possible, as most deaths from parvo occur within 48 to 72 hours after symptoms begin.

How is Parvo in Dogs Diagnosed?

A veterinarian diagnoses parvo by taking the dog’s history, noting the dog’s clinical signs and performing an examination; samples of stool and blood are also required. The diagnosis is then confirmed by lab testing of the samples. It is essential to begin treatment as soon as a dog has been diagnosed. With proper veterinary care, the survival rate of dogs who contract parvo can be up to 90 percent, but without treatment, the mortality rate is more than 80 percent.

How is Parvo in Dogs Treated?

Because there are no medications available that can kill the parvovirus once a dog is infected, treatment consists of hospitalization and supportive care, including:

  • Intravenous fluids to combat dehydration and replenish electrolytes

  • Anti-nausea medication

  • Antibiotics to prevent secondary bacterial infection

  • Isolation

  • Temperature control to prevent hypothermia

There is no cure for parvo at this time, but studies involving the use of antibody therapies that target the virus are currently being conducted and have promising results.

How to Prevent Parvo in Dogs

The best way to keep dogs safe is to make sure they are up-to-date on their vaccines. Puppies should be given the parvo vaccine (DHLPP) starting at six to eight weeks of age, then repeated every three weeks until the puppy is 16 weeks old. After that, the vet will give your dog booster vaccines every year.

Other important points: Before they’re fully vaccinated, puppies should be kept away from areas that could potentially be contaminated with parvo, such as dog parks, pet stores, and groomers. Don’t allow them to play with other dogs unless those dogs have been fully vaccinated.

Indoor areas where dogs congregate should be fully disinfected with dilute bleach or other commercial products, like Rescue or Trifectant. Fecal matter should be removed from both indoor and outdoor spaces as well. It’s important to note that even after dogs recover from parvo, they can still be contagious for up to two weeks, so it’s best to keep them away from other dogs until after that time has passed.

The bottom line: Good hygiene and preventive measures will go a long way toward keeping your dog healthy and safe.


Abbie Deleers, LVT

Abbie Deleers is a licensed vet tech and founder of the nonprofit organization Vet Techs Without Borders. She enjoys traveling with animal rescue groups, swimming with sharks, and outdoor activities with her husband and their Siberian Husky in the beautiful Pacific Northwest.