Editor’s note: Have you seen the new Catster print magazine in stores? Or in the waiting area of your vet’s office? This article appeared in our January/February 2017 issue. Click here to subscribe to Catster and get the bimonthly magazine delivered to your home.

Cats are susceptible to a variety of viral villains. One of the most challenging culprits is the virus that causes feline panleukopenia (pronounced “pan-luke-oh-pee-nee-a”), a highly contagious viral disease caused by a parvovirus. Most people mistakenly consider parvovirus a dog disease only; however, all felids, as well as raccoons, mink, and foxes, are also susceptible.

Panleukopenia is sometimes mistakenly referred to as “feline distemper,” which probably started because some of the symptoms are similar to those of dogs with distemper. But the virus that causes canine distemper is a completely different virus that is in no way related to the parvovirus that causes feline panleukopenia.
What you’ll see Symptoms of panleukopenia are similar to those in dogs with
parvovirus: fever, vomiting, diarrhea (possibly bloody), and poor appetite. The symptoms are explained by the propensity of the virus to attack cells in the body that are rapidly dividing, namely cells of the digestive system and the bone marrow.

Virally induced damage to the intestinal tract leads to vomiting, diarrhea, and poor appetite. Infection of the bone marrow impairs its ability to produce white blood cells, leading to a low white blood cell count. This explains the name of
the disorder: In Latin, “pan” means all; “leuko” means white; and “penia” means “decreased amount.” Cats with panleukopenia have low numbers of all white blood cell types.

How your cat gets it

It is most commonly transmitted when a vulnerable cat comes into contact with the feces, urine, blood, or nasal secretions of an infected cat. Contaminated objects like bedding, cages, shoes, clothing, hands, and food bowls can harbor and transmit the virus. It can also be transmitted from the mother to the developing kittens in her uterus.

Although it can infect cats at any age, kittens aged 3 to 5 months are particularly susceptible. These kittens often experience severe clinical signs, such as profuse diarrhea, frequent vomiting, abdominal pain, high fevers, and marked lethargy. Owners of affected cats often report finding their cats with their heads hanging over their water dish. With their small body size, kittens can rapidly become dehydrated.

A presumptive diagnosis is usually made based on the age and vaccination status of the cat and the clinical symptoms. Because panleukopenia is caused by a parvovirus, the rapid in-house parvovirus tests for dogs will also detect the virus in feline feces. Although the test has some limitations in cats, it does allow immediate, in-house detection of the virus in just a few minutes, confirming the diagnosis.

What to do

There are no medications that kill the virus. Treatment consists of aggressive supportive care with intravenous fluids, antibiotics, anti-nausea drugs, and nutritional sustenance. Severely affected kittens or cats might require plasma or blood transfusions.

The prognosis for recovery is guarded. Mortality rates are high, and most kittens younger than 8 weeks old don’t make it. Older kittens, if they survive the first 48 hours of hospitalization, may pull through.

Kittens who contract the virus in utero, if they survive, may be born with a brain disorder called cerebellar hypoplasia. The cerebellum is responsible for balance and coordination. Because these kittens have an underdeveloped cerebellum, they go through life a little clumsy and ungraceful but are otherwise fine. Due to the contagious nature of the disease, hospitalized cats should be strictly isolated from other cats. Cats who recover from panleukopenia are believed to be immune from the disease for the rest of their lives.

Don’t let it happen

The best way to treat any problem is to prevent it in the first place. Fortunately, vaccination offers safe and effective protection.

Initially, kittens receive immunity from the antibodies in their mother’s milk. This immunity only lasts a few weeks, however. As the kittens’ antibody levels drop, they become vulnerable to infection. To best protect kittens, they should be vaccinated against the virus. The initial vaccine is given between 6 and 8 weeks of age, then every two to four weeks thereafter until about 16 weeks of age.

Panleukopenia can be a major cause of mortality in cats in shelters and rescue homes. With rare exceptions, all felines in a cattery or shelter more than 6 weeks of age should be vaccinated, regardless of physical condition and pregnancy status.

The parvovirus that causes panleukopenia in cats is highly resistant to some disinfectants and may survive in the environment for several months. This has significant implications in shelters and catteries trying to limit the spread of the disease. Disinfectants containing sodium hypochlorite (bleach) have been shown to be effective in killing the virus in the environment.

About the author: Dr. Arnold Plotnick is the founder of Manhattan Cat Specialists, a feline-exclusive veterinary practice on Manhattan’s Upper West Side. He is also an author of The Original Cat Fancy Cat Bible. Dr. Plotnick is the former Ask the Veterinarian columnist for CAT FANCY magazine, and is a frequent contributor to feline publications and websites, including his own blog, Cat Man Do. He lives in New York City with his cats, Mittens and Crispy. Follow him on Facebook and Twitter.