Parvovirus in Puppies — What You Need to Know
Tags: Biology, Health, Veterinary, Dogs, Virus

By Megan Richman, D.V.M.

What is parvo?

Canine parvovirus (CPV), aka parvo, is a highly contagious and potentially deadly virus that can affect all dogs. Parvo is most common in unvaccinated dogs ages 6 weeks to less than 1 year old. There are two forms of Parvo — an intestinal and a cardiac.

Intestinal CPV

The intestinal form of parvo is by far the most common form. Intestinal parvo severely lowers the dog’s ability to absorb nutrients. Infected dogs quickly become dehydrated and weak from a lack of protein absorption. The classic clinical signs of this form include lethargy, vomiting, anorexia/not wanting to eat, and bloody diarrhea. You may also notice your puppy having pale gums, a low temperature or a painful belly.

Cardiac CPV

The cardiac form targets and destroys the heart muscle. Unfortunately, this form of CPV usually leads to a sudden death or death after an episode of difficulty breathing as a result of fluid accumulation in the lungs. You may or may not see the clinical signs of the intestinal form. Thankfully, this type of CPV is extremely rare thanks to diligent vaccination of breeding dogs.

Spread of CPV

Dogs get and spread this virus via direct dog-dog contact. They can also get the virus by coming into contact from contaminated feces, environments (kennel, bowls, leashes, collars, clothing), or people (infected clothing, hands, bottom of shoes). Unfortunately, it takes a small amount of infected feces for a dog to become infected with parvo. The virus is heat and cold resistant and can survive up to 5 years indoors or 1 year outdoors.

Parvo can spread via fomites — things like shoes and clothes that come in contact with a dog with parvovirus.

Young puppies are specifically prone to getting this virus due to the fact that their own immune systems may not yet be fully developed to fight off an infection by the time the immunity provided by their mother’s milk wears off.

I think my dog has parvo, what do I do?

If your dog has any of the above clinical signs, most notably lethargy, vomiting, bloody diarrhea or not eating, please see a veterinarian ASAP! Even before any testing is done, a history with these signs and the patient being a young dog/puppy will make a veterinarian think CPV!

What should I expect at the vet?

The first thing your veterinary hospital will do is run a parvo test that takes about 5 minutes and can be done at the hospital. It is a quick and easy way to get an answer but can get false negatives, meaning the parvo test is negative but the patient actually has the virus. Even if the test is negative but the patient is showing classic clinical signs, parvovirus is still highly suspected.

Your vet will likely want to run several blood tests. This is to see your pup’s white blood cell count, glucose/blood sugar level, lactate to measure perfusion and electrolyte values. Unfortunately, since CPV can be a fatal virus, your veterinarian will have a serious conversation with you about treatment options. Most deaths from parvovirus occur within the first 2–3 days after clinical signs begin. The mortality rate of dogs with parvo that receives no treatment is an astounding 91%, versus those that are hospitalized is about 10–25%. If your puppy is showing clinical signs, hospitalization will be strongly recommended. Hospitalization helps to stabilize and provide appropriate supportive care.

Puppies hospitalized for parvovirus have a much higher survival rate than those that go without hospitalization

Hospitalizing a parvo patient at an emergency hospital is typically about $2,000–3,000 for the first day. Patients may require hospitalization for 3–5 days depending on how sick they are. The reason this cost is so high is not that your veterinarian is trying to rip you off, but because your puppy is extremely sick and requires intensive care. This means your puppy will be put in an isolation ward to make sure the virus is not transmitted to other hospitalized patients, nurses or doctors. Your puppy will also have an IV catheter put in to receive fluids. They will be given anti-nausea medications, pain medication, potentially antibiotics, and have blood tests performed to determine the severity of illness. A naso-gastric tube may be placed in your puppy to provide nutritional support.

If hospitalization is not financially possible, there is an outpatient protocol. It is very important to know it has a much higher mortality rate than hospitalization. The outpatient protocol will include learning how to give fluids and anti-nausea medications under the skin, checking the temperature, and giving oral medications. It should also include daily returns to the veterinary clinic to check electrolytes and blood glucose levels.

How to prevent CPV

The key to preventing Parvo is vaccination and keeping your puppy away from public areas until they are fully vaccinated. This means that your puppy needs to receive all 3 sets of puppy vaccines 2 weeks apart. Adult dogs should receive a yearly booster or have titers performed to ensure adequate protection. If your puppy is not yet fully vaccinated, keep them away from dog parks, puppy classes, doggy daycare, kennels, groomers, parks or pet shops. All training programs should try to reduce exposure of disease by requiring vaccinations, veterinary visits, and isolation of sick animals. Please avoid contact with infected dogs or dogs of unknown vaccine history.

Unfortunately, despite doing everything right, your puppy or dog still may acquire CPV. A small percentage of dogs that receive all 3 sets of vaccines do not develop a protective immunity and can remain susceptible to infection.

About the Author

Megan Richman is a Doctor of Veterinary Medicine, obtaining her DVM from UC Davis in 2019. She practices veterinary medicine at Pet Emergency and Specialty Center in the greater San Diego area.

This blog post is sponsored by Fluxergy. We are bringing our point of care PCR device to the veterinary market.