Canine Parvovirus

What is parvo?
“Parvo” is the most common deadly disease we see in puppies. It is spread by the Canine Parvovirus, which typically causes extreme vomiting and diarrhea. While a terrible disease, it is also completely preventable by making sure your puppy gets vaccinated appropriately.

How does a dog get parvo?
Parvo is extremely contagious! A dog or puppy acquires parvo through oronasal exposure to contaminated feces. Keep in mind that the parvovirus can live in the environment for months to years! This means that a dog can defecate somewhere, and your dog can get parvo by sniffing that grass a year later (when the feces is all but gone). The virus is also easily transferred on clothing, shoes, hands, etc. This means that you could actually walk the virus into your home.

What are the signs of parvo?
The most common symptoms associated with parvo are inappetance, fever, vomiting, and diarrhea (that may or may not be bloody). Young puppies (less than 8 weeks) may also develop myocarditis (infection of the heart) that can lead to heart failure. If a pregnant dog is exposed to parvo for the first time, her fetuses are at risk for myocarditis , and the entire litter will usually be affected. These litters will usually all die immediately or soon after being born. One of my worst veterinary experiences, thus far, was euthanizing an entire litter of newborn puppies after their mom came down with parvo.

How do you treat parvo?
I have heard of all sorts of crazy “at home” treatments that people have read about on the internet, from feeding raw eggs to giving pedialyte enemas. The short of it is that, if you have a young dog or puppy that is showing any symptoms of parvo, you need to get it to a vet immediately. The sooner you start treatment, the better the chances that your puppy will survive! That being said, even with the most valiant of efforts, puppies can still not make it. Our clinic saves about 90% of the parvo cases that are hospitalized.
Parvovirus attacks the inner lining of the intestines. This does two things. First, it takes away the puppy’s ability to absorb water, which causes the puppy to get dehydrated. Second, it takes away the protective barrier that is normally in place to prevent bacteria from absorbing into the bloodstream. Dehydration and septicemia (infection of the blood) are the two things that puppies are most likely to die from. Treatment involves keeping the puppy hydrated with IV fluids, and keeping them on injectable antibiotics to prevent bacterial infections. (A puppy with parvo will vomit up any oral medications or fluids you give them!) We then have to wait until their body can clear the parvo infection and regrow a healthy intestinal barrier. This usually takes a minimum of three days, but can take much longer.

What can I do to protect my puppy from parvo?
Luckily, there is a vaccine that protects against Canine Parvovirus. The important thing to remember is that one or two vaccines will not guarantee that your puppy is protected. The reasoning for this is that a puppy gets maternal antibodies from its mother, which protects them when they are very young. The unfortunate thing about the maternal antibodies is that they make the vaccine ineffective. The idea is that the vaccine will take over, once the maternal antibodies disappear. The maternal antibodies go away at any point between 6-16weeks of age. We start giving parvo vaccines at 6 weeks of age, and then revaccinate every 3 weeks, until that puppy is 16 weeks of age. This ensures that, no matter when the maternal antibodies go away, that puppy is protected.

A quick note on vaccines: I recommend getting them from a veterinarian. We see a lot of puppies that get parvo who received vaccines from a feed store. This could partly be explained by the vaccines not being given at appropriate times by the owner, but could also be that the vaccines were not handled properly. If a vaccine gets too warm, it becomes ineffective. I worry that the vaccine might get too warm on the drive home from the feed store.

Also, I usually recommend avoiding public dog parks until a puppy has received all of its vaccines. While it is very important for puppies to get socialization at a young age, just make sure it is with other vaccinated dogs.

Can an adult dog get parvo?
I have seen parvo in dogs over a year of age that were not properly vaccinated, but it is mainly a puppy disease. An adult dog that received its entire series of puppy shots, as well as a booster at a year of age, should not get parvo.

I had a parvo puppy at my house. How do I disinfect my house and yard, so that it is safe to bring another puppy here?
The short answer is you can’t. The only thing that will kill parvo is bleach at a particular concentration (1 part bleach to 30 parts water). This can be used in the house and on hard surfaces, but there is no way you can guarantee that you have disinfected everything. Also, bleach will not work on organic surfaces, such as the yard or soil. Sunlight will break down the parvovirus, but this takes time. No one really knows exactly how long the virus lasts, but it can take over a year! To be on the safe side, I tell people to wait 2 years before bringing another puppy into that household. If someone wants to bring another puppy into that household, I recommend that they get an older puppy that has finished its entire series of shots.

Ryan Roberts, DVM