Canine Parvovirus: What You Need To Know

Medical articles

Canine Parvovirus (CPV) is a highly contagious virus that can cause death within 48 to 72 hours of a dog showing symptoms. It can affect any breed, while some are more susceptible than others. Unvaccinated puppies that are four months old or younger are most at risk.

If you suspect your dog has been exposed or shows symptoms including vomiting or diarrhea, seek veterinary attention immediately. Time is of the essence.

Following a recent outbreak of parvo in dogs, we’ve updated this page with all the information pet owners need to know about this virus.

You’ll read more about:

  • How the Virus Works

  • Canine Parvovirus Symptoms and Treatment

  • History and New Developments

  • A Customer Story

  • How to Keep Your Dogs Safe from Parvo

It’s important to understand just how easily parvovirus in dogs can spread. The pathogens can be in pet stores, dog parks, and other places a pet frequents. It can also live for a long time in cold temperatures and on surfaces such as toys, bed, grass, and dog bowls.

As a result, an infected dog doesn’t need to make contact with another dog to transmit the disease. Instead, another dog can become infected after coming into contact with any surface with pathogens on it.


Canine Parvovirus Outbreak in Michigan: 2022

A recent breakout in the U.S. took place in Michigan’s northern Lower Peninsula region in August 2022. More than 20 dogs died from the illness, and on August 24, the State Veterinarian Nora Wineland, DVM, confirmed parvovirus as the cause.

The announcement came as the result of testing through the Michigan Department of Agriculture and Rural Development and the Michigan State University Veterinary Diagnostic Laboratory.

“Dog owners across Michigan must work closely with their veterinarians to ensure their dogs are appropriately vaccinated and given timely boosters to keep their pets safe and healthy,” Wineland said in a press release.

“Protecting Michigan’s dogs is a team effort.”

Read More About Puppy Vaccinations

Embrace Pet Insurance has become part of that effort as team members travel to Michigan in early September to help administer free vaccines and offer gift cards to those who recently paid for one. And, we’ve ensured the information on this page is accurate and up-to-date.

How Parvovirus in Dogs Works

Infection occurs when a puppy or adult dog ingests the virus. To successfully infect a dog, CPV needs the help of rapidly dividing cells, with the first cells to be attacked being the lymph nodes of the throat.

After incubating there for a few days, the virus spills into the bloodstream, traveling to the bone marrow and intestinal cells. Within the bone marrow, CPV destroys white blood cells. This process makes it easier for viral particles to invade and wreak havoc on the gastrointestinal (GI) tract.

A dog’s intestines have rapidly dividing cells. There, CPV does the most damage by leaving its intestines unable to absorb nutrients.

Eventually, bacteria, which is normally confined to the GI tract, spills out of the intestines and into the bloodstream. This causes significant blood loss through diarrhea and widespread infection throughout the dog’s body.

Canine Parvovirus Symptoms

Severe diarrhea (oftentimes odorous or bloody) and nausea (which further weaken a dog's system) are the primary symptoms. Lethargy, depression, loss or lack of appetite, followed by a sudden onset of high fever may also occur.

The typical incubation period is 3 to 7 days between initial infection and onset of first symptoms.

Diagnosis, Treatment, and Prognosis

This highly contagious gastrointestinal disease normally affects puppies, but unvaccinated dogs of all ages are susceptible.

Read More About What Vaccinations Adult Dogs Need

For unknown reasons, some breeds are at a higher risk of infection including Rottweilers, Doberman Pinschers, Labrador Retrievers, American Staffordshire Terriers, and German Shepherd Dogs.

Diagnosis is confirmed with an enzyme-linked immunosorbent assay (ELISA) test, with results being available in about 15 minutes.

Parvovirus in dogs treatment consists of intensive veterinary management including intravenous fluids to control dehydration, and antibiotics for infection, which requires a costly hospital stay.

Often, the cost is prohibitive for many owners, with euthanasia being the alternative for severely affected dogs.

CPV is not always fatal, but those dogs who die usually do so as a result of dehydration and/or secondary bacterial infection.

Parvo in Dogs: A Bit of History

Nearly every mammal species, humans included, has its own parvovirus, with each virus being specific for which animal it can infect. For instance, the pig parvovirus will not infect people, the canine virus will not infect cats, the human virus will not infect dogs, etc.

The original canine parvovirus, discovered in 1967 and called CPV-1, did not represent much threat - except to newborn puppies. Experts believe it mutated from the already well-known feline panleukopenia virus (FPV).

Around 1978, a new variant, CPV-2 emerged and no dogs had immunity against the virus, which resulted in a CPV epidemic. By 1979, a second virus—CPV-2a—emerged, which seemed even more aggressive.

In 2000, yet another virulent strain known as CPV-2c was discovered in Italy, with the first case in the United States being confirmed in 2006.

Parvovirus in Dogs: A Pet Owner’s Story

Barbara Sorg did everything right. So, how did she end up with a $15,000 veterinary bill?

Despite taking every precaution, her litter of eight-week-old English Shepherd puppies was infected with the canine parvovirus (CPV). Each puppy spent varying amounts of time in the intensive care unit, with four of them surviving and one being humanely euthanized.

Experts say CPV particles are literally everywhere in every environment, except those environments that are regularly disinfected.

Highly-resistant to most cleaning products, contaminated areas, such as floors, walkways, driveways, crates, etc., can be disinfected with one part bleach to 30 parts water.

Even then, sterile environments can be quickly re-infected, as the virus is shed in large amounts in the stools of infected dogs for several weeks following infection. It can be carried on a dog's feet and hair, as well as carried on shoes, clothing, tires, pet crates, and other animals.

To make matters worse, CPV is extremely hardy and viral particles are capable of surviving for months in the environment—even through winter.

"I have no idea where they picked up the parvo," Sorg said. "I assume it came in on one of the shoes of the many visitors, or the shoes of prospective puppy buyers, as the puppies were only on my property.

“It could have come in on one of my family members' shoes, or it could have been brought to my yard by an infected raccoon. We will never know."

Preventing Parvo in Dogs

Parvo is a highly contagious and often lethal gastrointestinal disease. Preventing parvo in dogs doesn’t have to be difficult. To keep your puppy safe, experts recommend the following:

Vaccinate your puppy. Puppies have immunity from their mother early in life, but should receive their first vaccination between 6 and 8 weeks of age and then two boosters at three-week intervals. Many experts recommend the final vaccination occur at 16 weeks of age to avoid maternal antibody interference.

Avoid taking your puppy to high-risk areas such as dog parks, pet stores, doggie day care, boarding kennels, and other areas dogs frequent until the puppy has received its complete set of vaccinations.

Before your puppy is vaccinated, clean and disinfect your home with a cleaner that’s proven to kill the parvovirus. You can check online or ask your vet for recommendations.

Invest in Dog Insurance

Stay prepared with insurance for dogs. Getting dog insurance for your puppy may help you save money on veterinary bills and expensive medications if something happens in the future.