PET HEALTH

What Is Parvo & How Do Dogs Get It?

Three Minutes
Oct 31, 2022

Canine parvovirus (CPV), aka parvo, is a dangerous and potentially fatal virus that can affect the gastrointestinal tract of puppies. Yes, parvo can be scary, but vaccination can prevent it. And if your pooch does become infected with it, the prognosis need not be grim. What matters is how quickly you get them diagnosed and started on treatment. Because of this, it’s important to understand how parvo in puppies works, to learn how to protect your dog against it, and to know the symptoms to watch out for.

How Does Parvo in Dogs Work?

Parvo is a potentially-lethal infection that can strike puppies 6 – 20 weeks of age.3 If left untreated, it attacks the gastrointestinal tract in young puppies. A rare variant of the virus can also cause inflammation of the heart in newborn pups. However, modern vaccines have made it a much less dangerous threat.

Parvo first emerged in European dogs in 1976, but its exact origins are unknown.3 Within two years it became a worldwide epidemic. The parvovirus has also been found in wolves, coyotes, foxes, skunks, and racoons. It’s theorized to have come about as a mutation of feline panleukopenia virus (FPV).3

How Do Dogs Get Parvo?

Pups usually encounter the parvovirus in shelters and other environments that bring them into close contact with an infected dog. Parvo is a highly contagious virus that primarily spreads through infected feces, but secondary transmission can occur if they come in contact with a person or object that has touched parvo poop. The virus can be carried on dog feet, shoes, toys, and even water bowls.

The parvovirus is fairly stable and can survive up to a year outdoors.4 This means sidewalks and local dog parks could be infected and you’d never know. Because it can also infect wild animals, your dog could be exposed to the virus while exploring the outdoors in general. Add to that the virus’s ability to survive outside its host, and you have the perfect storm for a highly contagious disease. This is why veterinarians recommend puppies stay “paws off the ground” before they’re fully vaccinated against the virus.

Can Humans Get Parvo From Dogs?

Dogs cannot transmit parvo to humans, nor can humans transmit parvo to dogs. While humans are susceptible to the virus, it’s a different strain. Dogs are at risk for CPV-2a and CPV-2b.5 Meanwhile, humans are susceptible to parvovirus B19.6

Stages of Parvo

Once it has found a host, the parvovirus incubates for 3 – 7 days. It will seek out rapidly dividing cells to help make copies of itself throughout the body. Parvovirus often attacks the lymph nodes, invading white blood cells so that it can be carried through the vascular system. This has the added effect of causing the host's body to target and destroy many of its own white blood cells, essentially crippling its immune system.3

From the bloodstream, parvo targets additional tissues like bone marrow and the lining of the small intestine, called the epithelium. This prevents the intestine from replacing dead epithelium cells with new ones. As a result, the host is unable to absorb nutrients. In severe cases the lining becomes thin enough to allow intestinal bacteria to spread to other parts of the body. Septic toxins enter the bloodstream and, unhampered by an already-weakened immune system, can lead to septic shock and death.3

Parvo Symptoms in Dogs

Dogs with parvo will display a number of symptoms, including:3

  • Lethargy
  • Depression
  • Lack of appetite
  • High fever
  • Diarrhea, sometimes with blood
  • Vomiting
  • Weight loss
  • Muscle weakness

If you notice any of these symptoms in your pooch, schedule a vet appointment right away. All of the above parvo symptoms are dangerous in puppies. Even if it’s not the parvovirus, something may still be seriously wrong.

Parvo Treatment

If your dog is diagnosed with the virus, they will likely have to spend multiple nights hospitalized as the vet administers an IV to help replenish fluids lost during vomiting and diarrhea. Anti-nausea and anti-diarrheal medications may be administered as well.3 Because parvo can cause septic shock, your dog may also be given antibiotics to combat additional infections.5

Parvo Recovery

Once your dog is released from the hospital, it may take time for them to regain the weight and get their energy back. Work with your vet to ensure your pup is getting the nutrients they need. This may mean you purchase higher-quality dog food or introduce some wet foods into their diet. Encourage them to eat and stay hydrated.

Preventing Parvo in Dogs

Fortunately, the parvo vaccine has come a long way since the virus first arrived on the scene in 1976. Because the virus is so lethal and can spread so quickly among dogs, the parvo vaccine is considered a “core vaccine” — an essential immunization recommended by all veterinarians.

Core vaccines are administered in rounds, starting at 6-weeks-old and lasting until a puppy reaches 16 weeks. Your pup will need a parvo vaccine booster 1 year later, and additional boosters every 3 years following.3

Since parvo is transmitted through feces and highly infectious, it’s wise to keep your puppy from public dog spaces until they’re fully vaccinated. Yes, this means avoiding the dog park until they’re 16 weeks old. However, since socializing puppies is important, you can find fully vaccinated adult dogs for them to interact with in controlled settings.

Can Older Dogs Get Parvo?

Although it’s typically associated with puppies, adult and senior dogs can get parvo too if they are unvaccinated or not fully vaccinated with the full course of boosters.7 So if you do want your puppy to socialize with an adult dog, it’s important to verify that the adult dog has had their parvo vaccinations.

How Pet Insurance Can Help

Parvo treatment costs can easily exceed $1,000. However, dog insurance can help cover the hospitalization and medication costs.2 For more info, check out “What Pet Insurance Covers.”

At MetLife Pet Insurance, winner of the “Pet Insurance of the Year” Award, we’re committed to helping you keep your pets happy and healthy, whether that means learning all there is to know about your pets or protecting them with an insurance policy.1 MetLife even offers optional wellness coverage that helps cover vaccinations, including the parvo vaccine.2 Get a quote today to see if dog insurance fits into your lifestyle.

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