Can A Vaccinated Dog Still Get Parvo?

You’re planning to get your dog vaccinated against parvovirus, but you might be wondering how effective the shot really is. After all, can dogs with the parvo vaccine still get infected?

The Dodo spoke with Dr. Linda Simon, a veterinary surgeon and veterinary consultant for Five Barks, and Dr. Michelle Burch, a veterinarian from Safe Hounds Pet Insurance, to find out just how a vaccinated dog might still get parvo.

Parvo is a life-threatening disease that affects your dog’s intestines.

“Canine parvovirus is a highly contagious virus that can cause death in all unvaccinated dogs but typically affects puppies,” Dr. Burch told The Dodo.

That’s why the parvovirus vaccine is one that every dog needs (aka a core vaccine).

While the parvovirus vaccine is incredibly effective, there are some instances where a vaccinated dog can still get parvo.

“Unfortunately, even those who are already vaccinated against parvovirus could potentially become infected,” Dr. Simon told The Dodo.

One way this happens is if your dog’s exposed to parvovirus before he’s received all the necessary doses of the vaccine.

“Many owners do not realize the vaccine protocol for puppies includes booster vaccines every three to four weeks until 16 weeks of age,” Dr. Burch said. “If the booster vaccines were not continued through 16 weeks of age, your dog might not have mounted an appropriate immune response.”

But sometimes even dogs who completed the required vaccination rounds can still get parvo.

“It is technically possible for those who are fully vaccinated to become infected,” Dr. Simon said. “This, however, is rare.”

This can happen if your dog’s sick when he receives his parvo vaccines, since his impaired immune system wouldn’t have been able to create all the antibodies he needs to stay safe from the disease.

“Despite being vaccinated for parvovirus, dogs who have a breakthrough infection may not have responded to the vaccine appropriately due to the individual's immune system,” Dr. Burch said. “The body may not have produced the appropriate antibodies needed to protect against infection.”

Sometimes, your dog’s parvo vaccine can be less effective if it wasn’t stored properly before he received it.

“Vaccine vial handling can also cause a vaccinated dog to contract parvovirus,” Dr. Burch said. “Vaccine vials must be shipped and stored at appropriate temperatures. The parvovirus vaccine must stay between 36 and 46 degrees Fahrenheit to maintain efficacy.”

Dogs often get parvo by coming into contact with poop from an infected dog.

The problem is even if you pick up the poop, the virus itself is pretty strong, can survive even in extreme temperatures and is resistant to a lot of household cleaners. So if an infected pup has an accident indoors at your dog’s daycare facility, for example, your pup is at risk — even if the mess is cleaned up.

“Parvovirus is highly infectious and can cause dogs to become extremely unwell,” Dr. Simon said.

That’s why the best way to keep your dog from getting parvo is by getting him vaccinated — and making sure he receives every dose.

Parvovirus symptoms can be pretty serious and even life-threatening.

Signs of parvo in dogs can include:

“Thankfully, dogs who are vaccinated do not tend to develop signs as severe as those who are unvaccinated,” Dr. Simon said.

If you notice any of these symptoms, even if they’re mild, bring your dog to the vet right away because parvo can be fatal.

The parvo vaccine is super important because it’ll help your dog make antibodies that’ll protect him from the widespread, life-threatening disease.

“Vaccines work by safely triggering the immune response and allowing the dog to create antibodies,” Dr. Simon said. “This means if they are exposed to parvovirus, they should be able to fight it off without becoming unwell.”

The parvo vaccine is often designed to build those antibodies.

“Canine parvovirus vaccines are predominantly modified live vaccines (MLV),” Dr. Burch said. “When the MLV vaccine is administered to a dog, the body recognizes the parvoviral antigen, and the immune system begins to produce plasma cells and memory B cells. These cells will then produce IgG antibodies as the immune response matures.”

Keep in mind that a vaccinated adult dog will need annual booster shots for parvo. Making sure your dog stays up to date on his shots will keep him protected long after his initial vaccinations.

“As antibodies wane with time, your dog needs to receive regular booster vaccines,” Dr. Simon said.

“Dogs who have three to five encounters with the vaccine will typically develop the highest amount of antibodies to protect from infection,” Dr. Burch said.

And while some fully-vaccinated dogs can still get parvo — remember, this is rare — the vaccine will usually keep your pup completely safe.

“For the vast majority, though, vaccination prevents them from ever becoming unwell,” Dr. Simon said.

So as scary as it sounds, vaccinated dogs can still get parvo, though it’s highly unlikely. You should still get your dog vaccinated for it since parvovirus is a serious, scary and life-threatening disease, and the vaccine is normally incredibly effective.

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