How Do Cats Get Parvo?

Parvovirus is a highly contagious, persistent, mostly species-specific virus that causes a range of severe illnesses across many species. Unfortunately, that also means that your cat can get parvo. In cats, parvo is sometimes called distemper, and it is caused — just to be confusing — by a strain of parvovirus called feline panleukopenia virus (FPV). 

What you need to know is that FPV is most often spread in cats through contact with infected poop (fecal matter). FPV is species-specific to cats, and the cats most vulnerable to infection are kittens, unvaccinated cats, and cats living with many other cats. The best way to prevent disease is to keep your cat up-to-date on their vaccinations and regular vet check-ups.

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What is parvo in cats?

Parvo in cats is caused by FPV. This virus attacks rapidly dividing cells in the body, leading to severe gastrointestinal disease, immunosuppression, and neurological symptoms in infected cats. The disease progresses quickly and can have a high mortality rate, so it is important to know when to suspect that your kitten or cat has FPV and to contact your veterinarian immediately.

How do cats get parvo?

Parvo is spread through infected body secretions:

• Saliva

• Urine

• Vomit

• Feces

The most frequent source of parvo in cats is contact with infected fecal matter. Parvo lives for months to years in the environment and is difficult to disinfect. This means that it is also common for items, people, and other animals to spread parvo by coming into contact with infected secretions and then spreading that to a cat. The good news is that, although humans can inadvertently spread FPV, they cannot contract FPV from cats — nor can other household pets, including dogs. 

Not all cats become sick when exposed to parvo. Kittens are far more likely to get sick than adult cats, and they’re more likely to have a severe infection. This is due to a cat’s body developing a strong immune response to the virus if they’ve been exposed to it in the past. (This includes FVRCP vaccines.) In fact, if a cat survives FPV-caused sickness, they are immune for life. 

In addition to kittens and unvaccinated cats, cats living with many other cats (such as those in colonies) are more vulnerable to becoming ill. This is due to the area’s high virus load as it starts to spread around a colony, in addition to elevated stress levels caused when cats live close to many other felines. 

Can cats get parvo from dogs?

Yes, cats can get parvo from dogs. Canine parvovirus strains cause feline distemper in cats, aka feline panleukopenia, and the reason is quite interesting. Canine parvovirus (CPV), which causes parvo in dogs, is actually a mutated form of feline parvovirus. 

When the virus first mutated, it changed the species-specific component of the virus and started infecting dogs instead of cats. Then canine parvovirus, CPV-2, continued to mutate and developed variants A, B, and C. These variants are what we have circulating through dogs today, and these variants, unlike the original CPV, can also infect cats. 

CPV infections and FPV infections in cats look essentially identical, and the veterinary medical community is still learning about this connection. It would seem that cats are an important force behind all the mutations in canine parvovirus, that they are an important source of the disease in dogs (especially in shelters), and the number of panleukopenia cases caused by CPV instead of FPV has likely been grossly underestimated.

What does that mean?

• Cats can get parvo from dogs in the form of CPV instead of FPV.

• Dogs cannot get FPV from cats, but they can get CPV if a cat is infected with it.

• Dogs cannot get FPV from cats. But, since cases of feline panleukopenia can be caused by CPV (and you can’t tell the difference), it is important to quarantine dogs and cats from each other if either shows signs of parvo — until the exact strain of parvo has been identified.

• Panleukopenia is the name of the disease cats get when they contract parvo, and it can be caused by FPV or CPV. It appears that CPV plays a larger role in panleukopenia infections than previously thought, meaning the risk of spreading parvo between dogs and cats is more significant than previously thought.

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Cat parvovirus symptoms

Cats with parvo can become quite ill very quickly. It’s important to be able to identify feline parvovirus symptoms, so you can take them to the vet for the help they need.

Early signs of parvo in cats include:

• Lethargy

• Decreased appetite

• Soft stool or diarrhea

As the disease progresses, you may notice:

• Anorexia

• Vomiting

• Diarrhea with or without blood

• Fever

• Dehydration

• Belly pain

In severe cases, symptoms of parvo in cats can include:

• Hypothermia

• Seizures

• Diarrhea that is mostly bloody

• Pale gums, possibly with pinpoint red dots

• An unsteady gait

Kittens who get parvo under the age of four weeks are at risk of the virus attacking cells still developing in the cerebellum of their brains, which controls coordinated muscle movements. It also impacts developing cells associated with their eyes. In addition to the above symptoms, a kitten this young can develop the following symptoms at any point in the disease progression:

• Blindness

• Head tremors

• Intention tremors (head tremors only when awake and focusing on something they want)

• A very unstable gait with high-stepping paws, and frequently falling sideways 

Feline parvovirus prognosis

The prognosis for feline parvovirus is unfortunately poor. Survival rates generally range from as low as 20 percent to 50 percent, at best. Cats who are concurrently infected with other diseases while their immune system is suppressed from parvo have the poorest prognosis. This often applies to young, unvaccinated kittens. Due to this, FPV is a common cause of fading kitten syndrome. The best way to increase the odds of survival if your cat is showing signs of parvo is to bring them to a veterinary clinic immediately. Early hospitalization and treatment provide the best chance of success. 

Cats who survive parvo are immune for life and may have a latent form of the virus in their body forever. There may be long-term health effects in cats who survive a panleukopenia infection. Kittens, in particular, can develop cerebellar hypoplasia or become blind if they were less than four weeks old when infected. These are lifelong conditions. 

If you want to avoid the risk of a FPV infection in your cat, keep them up to date on their vaccines. This is the most important method of prevention. If you haven’t picked a vet yet, here are a few tips to help you pick the right vet for your cat.

Commonly asked questions

Where does parvo come from?

Cats get parvo most often due to contact with infected fecal matter. This is frequently transferred into their environment through contact with other animals and people. 

How likely is it for a cat to get parvo?

Parvo is highly contagious, and many cats who are exposed to parvo will technically have it. However, not every cat with parvovirus in their body will become sick. Kittens, unvaccinated cats, and cats living with many other cats are far more likely to get ill from parvo.

Can fleas transmit parvo in cats?

It is unlikely that fleas will transmit parvo to cats. Despite some internet discussion, there is no research supporting significant parvo transmission by fleas. However, flea infestations can cause anemia in young kittens, sometimes severe enough to be fatal, and they can also transmit tapeworms. Concurrent diseases significantly worsen the prognosis for a cat with parvo, so an important part of treating parvo in cats includes flea control. 

References

Citarová, A., et al. “The Findings of FPV, CPV-2a, CPV-2b and FCoV in Cats with Signs of Feline Panleukopenia.” Berliner Und Münchener Tierärztliche Wochenschrift, vol. 135, Oct. 2022, pp. 1–6. Vetline, www.vetline.de/the-findings-of-fpv-cpv-2a-cpv-2b-and-fcov-in-cats-with-signs-of-feline-panleukopenia, https://doi.org/10.2376/1439-0299-2022-13.

Kruse, B.D., et al. “Prognostic Factors in Cats with Feline Panleukopenia.” Journal of Veterinary Internal Medicine, vol. 24, no. 6, 12 Oct. 2010, pp. 1271–1276. Wiley Online Library, onlinelibrary.wiley.com/doi/epdf/10.1111/j.1939-1676.2010.0604.x, https://doi.org/10.1111/j.1939-1676.2010.0604.x.

Porporato, Federico, et al. “Survival Estimates and Outcome Predictors for Shelter Cats with Feline Panleukopenia Virus Infection.” Journal of the American Veterinary Medical Association, vol. 253, no. 2, 15 July 2018, pp. 188–195. AVMA Publications, avmajournals.avma.org/view/journals/javma/253/2/javma.253.2.188.xml?tab_body=pdf, https://doi.org/10.2460/javma.253.2.188.

Rothrock, Kari. “Feline Panleukopenia.” VINcyclopedia of Diseases, Veterinary Information Network, 2 Oct. 2024, www.vin.com/members/cms/project/defaultadv1.aspx?pid=607&id=5444094.