Ask The Vet : Parvo Virus by Dr. Stefanie Wong

If you've ever owned a puppy, you've likely been told that you shouldn't take them outside until they've received their full course of puppy vaccinations. Ever wonder why? One of the major diseases we are protecting them against is something called Parvovirus. Parvovirus is a highly contagious disease that if untreated, is fatal.

What is Parvovirus?

Parvovirus is an extremely hardy virus – it's resistant to heat, cold, and even the most basic household cleaners. One of the most dangerous things about it is how long it can survive and thrive in the environment. It's spread by contact with infected stool – however the infective particles can transfer from the stool to the environment. From there, they can be carried around on the feet of other dogs, or even shoes of humans. Therefore, parvovirus can be found anywhere.

What are the symptoms of Parvovirus?

Parvovirus can affect all dogs, however unvaccinated dogs and puppies less than four months (or sixteen weeks) old are at the highest risk. After getting infected, there's a 3-7 day incubation period before they actually show symptoms of being sick. The most commonly seen symptoms are vomiting, severe diarrhea (with or without blood), lethargy and decreased or absent appetite. If your puppy is showing any of these symptoms (especially if they are unvaccinated or have not completed their puppy series) then they should be seen immediately to make sure they do not have parvovirus.

Can you test for Parvovirus?

If we suspect your puppy may have parvovirus, we often recommend running a parvo test. This is a test that we run in-house using a rectal swab to collect a small amount of stool. It takes just 10-15 minutes to run.

Why is Parvovirus so deadly?

Once inside the body, the virus will travel to attack the immune system (white blood cells) as well as the GI tract (stomach and intestines).

By attacking the immune system, it causes depletion of white blood cells (some puppies come in with zero to no neutrophils! – one of the important white blood cells for fighting infection). The lack of white blood cells means that the body cannot fight off infection – this means they are susceptible to any and all bacteria they come in contact with – pneumonia is a frequent complication of parvovirus.

By attacking the stomach and intestines, it causes severe vomiting and diarrhea. The severe vomiting and diarrhea causes severe dehydration – this can be life-threatening in itself.

How do you treat it?

Treatment is essentially supportive. We keep them on intravenous fluids in order to prevent dehydration, broad spectrum antibiotics in order to prevent against secondary infection, anti-nausea medications to try to prevent vomiting and encourage them to eat as well as anti-diarrheal medications to help fight the diarrhea. These puppies typically are in critical condition and therefore need very aggressive treatment and care in order to get better. The hospital stay is often anywhere from 5-7 days, some puppies need care for even longer than that. The most heartbreaking part of all of this is, even with these intensive treatments, some puppies will still not make it.

How do you prevent it?

The good news is that Parvovirus is 100% preventable, through vaccination. We vaccinate puppies with DHPP every 3-4 weeks from 8 weeks up through 16 weeks of age. DHPP stands for Distemper, Hepatitis, Parvovirus and Parainfluenza – the 4 diseases that this vaccine protects against. Each subsequent vaccine they receive after 8 weeks is a booster in order to bolster their immune system.