Feline Panleukopenia


What is Feline Panleukopenia?

Feline panleukopenia (also known as feline distemper) is a highly contagious viral disease of cats. The virus responsible for causing feline panleukopenia is very closely related to the virus responsible for causing parvo in dogs (it is not related to the virus that causes distemper in dogs even though the name suggests that it might be).  This virus invades rapidly growing cells, such as cells in the digestive system, bone marrow and lymph tissue. This virus is transmitted through feces and/or urine of infected cats; it can also be spread by contaminated items such as bowls, litter boxes and bedding. The virus can also be transmitted from an infected mother to the kittens while still developing in the uterus.


The virus is widespread in nature, making panleukopenia one of the most prominent feline diseases in the non-vaccinated cat population. It is very stable in the environment and can survive well both at room temperature as well as at lower temperatures. The virus is also very resilient and is not killed by many common disinfectants.

What are the symptoms of panleukopenia?

Generalized symptoms of panleukopenia include depression, lethargy, loss of appetite, fever, diarrhea and vomiting. When the virus attacks the intestinal tract it causes ulceration and sloughing of the intestinal epithelial cells, leading to bloody diarrhea, malnutrition, anemia and dehydration, which could progress to death of the cat. When the virus attacks the bone marrow and the lymph nodes it causes an overall decrease in the cat’s blood cells, which ultimately affects their immune system, leaving them vulnerable to secondary infections and septic shock. Cats with panleukopenia may also develop disseminated intravascular coagulation. If a pregnant cat contracts panleukopenia it can cause cerebellar hypoplasia in her offspring.

How is panleukopenia diagnosed?

Diagnosing panleukopenia is usually based on the cat’s medical history, vaccination status, clinical signs, physical exam and laboratory testing. A cat with a history of exposure to an infected cat or lack of their own vaccination with the visible signs of illness may be suspected of having panleukopenia.

A complete blood count (CBC) and differential of infected cats will show a reduced number of circulating white blood cells. Also a low level of circulating red blood cells (anemia) is also quite common.


There is a send out test that tests the cat’s stool sample for the virus.  A positive result of this test supports a panleukopenia infection. Alternatively, since this virus is related to the virus that causes parvo in dogs the in-clinic canine parvo test can also detect feline panleukopenia viral antigen in feline feces. This test is only approved and licensed for detecting canine parvovirus, and it is considered “off-label” use when used in a feline situation.

Blood testing can be done, but a positive antibody titre doesn’t necessarily mean an infection, it can result  from vaccination as well.

A chemistry panel and fecal flotation/smear may also be necessary to look for concurrent health problems that may need addressing to form a proper and effective treatment plan for your cat.

How is panleukopenia treated and prevented?

Since it is a virus that causes the initial problem, treatment is centered on supportive care. This means that the secondary problems that come up during the course of the infection are addressed individually with the goal of keeping the cat  alive long enough for an immune response to generate. Be prepared for  your cat to stay in hospital, as isolation and intensive care is needed to treat this infection.

IV Fluid Therapy: It is crucial to correct any dehydration the cat may be suffering from due to any vomiting and/or diarrhea. The fluids are best given intravenously. It is not recommended to re-hydrate a cat with panleukopenia by subcutaneous fluid injections.

Antibiotics: Another way this virus attacks is by creating sepsis of the circulatory system. The intestine is normally full of bacteria and when the virus ulcerates the intestine, this intestinal bacteria can get into the bloodstream. With the intestinal tract damaged, oral antibiotics are not recommended as they are not as effective as those given either as intravenous or intramuscular injections in this situation.

Control of Nausea: Patient comfort is an important part of treatment for this disease. Cats with panleukopenia can feel nauseated and may not want to eat.  Since the gastrointestinal tract may be too damaged for oral medication anti-emetics are given by injection.

Fluid supplementation: Abnormalities in blood chemistry such as low blood sugar or potassium levels can be addressed by picking appropriate fluids and/or by adding supplements to the fluids.

Blood transfusion: Severely affected cats that are also suffering from anemia may need blood or plasma transfusions.

Getting them to eat: Intake of water and food should only be restricted if the cat is persistently vomiting, otherwise feeding should be continued. Vitamin B12 injections are often given to cats who are not feeling well or have a decreased appetite. The B12 tends to perk them up and can help stimulate their appetite. If your cat does not want to eat at all, placing a feeding tube may also be needed to ensure your cat is getting the nutrients they need.

Hospital treatment for panleukopenia usually lasts 5- 10 days, but it can take up to a month for full recovery to be seen in your cat.

The best way to prevent your cat from getting panleukopenia is vaccination. Immunity to this virus is part of the RCP core vaccine given to cats (the “P” in the vaccine name stands for panleukopenia). Kittens are given this vaccine in a series of boosters, 4 weeks apart 2-3 times depending on their age. The vaccine is repeated one year later, then it changes to a 3 year schedule.


This virus is very hard to kill and get rid of when infected cats shed the virus into the environment. Thorough disinfection with a bleach solution is needed to clean up any areas, dishes, litter boxes or bedding used by infected cats. Cats discharged to continue their recovery at home should be isolated from other cats in the household for up to 6 weeks so not to spread the virus. Once a cat has recovered from the disease, they are considered immune to the virus and are not at risk for getting it again.