What is panleukopenia? 

Feline Panleukopenia Virus (Panleuk) is highly contagious, life-threatening virus that attacks the white blood cells and intestinal lining of young kittens or unvaccinated cats. The virus is very durable in nature, which means it can stick around for a long time and infect animals for up to a year if not removed! It is a very common virus in animal shelters.

How is panleukopenia spread?

The virus is shed mainly in feces and fomites. Fomites are objects that become covered in viral particles, and when another animal interacts with the object they become infected with the virus. Common fomites include toys, bedding, hands, food and water dishes, clothing, hair and carpeting to name a few. The virus can spread from one animal to many very quickly, especially with litters of kittens. An animal infected with panleukopenia virus can shed viral particles in its feces for up to 6 weeks! 

How long does it take for a cat to get sick? 

The incubation period, or period between contact with the virus and the appearance of illness, can be as short as three days or as long as two weeks, but four to six days is most common. 

What are the signs of illness? 

Since the virus attacks a cat’s intestinal lining and their digestive tract, clinical signs usually involve fever, vomiting, diarrhea (sometimes with blood), loss of appetite, dehydration, drooling, low energy level or lethargy, and abdominal pain. Kittens less than six months of age are most likely to be the sickest, and affected kittens can die suddenly.

How is it treated? 

Panleukopenia is treated with aggressive fluid therapy, antibiotics, pain control, anti-nausea medication, and supportive care. It is also essential that infected animals are isolated from all other animals and kept in an environment that is easy to disinfect to prevent spread of the virus. This is why your foster must stay at PAWS until it is cleared of disease!

Cleaning and disinfecting

Do I need to clean my house more than after a normal kitten or foster kitten? 

Yes! Panleukopenia is very durable and very contagious, and a very thorough cleaning of all contaminated environments (and any potentially contaminated environments) with a product that is proven to kill panleukopenia is absolutely essential. We recommend thoroughly cleaning your entire home now, and repeat the cleaning in 2-3 weeks in case anything was missed. Those viral particles can be persistent and sneaky!

What should I use to clean my house? 

Any household bleach will effectively kill panleukopenia infected environments. Use a 1:32 bleach-to-water ratio and make sure the bleach solution is in contact with the infected surface for at least 10 minutes before rinsing or wiping clean. You can also use a "super concentrated" 1:10 bleach-to-water solution, but make sure you have really great ventilation!

Another product that works to kill panleukopenia virus is accelerated hydrogen peroxide. The best accelerated hydrogen peroxide product we have found is called "Rescue." Please note, accelerated hydrogen peroxide is NOT the same as Oxiclean or other simple hydrogen peroxide products that do not contain "accelerated hydrogen peroxide" specifically (check the active ingredient list!).

How should I clean hard surfaces like tile, food and water bowls, plastic toys, cages, or carriers?

Panleukopenia viral particles on hard surfaces, such as bowls, carriers, crates, and plastic toys, are readily killed by bleach solutions. Use a 1:32 or 1:10 bleach to water solution and make sure the bleach solution is in contact with the infected surface for at least 10 minutes before rinsing or wiping clean.

How should I clean soft surfaces like bedding, clothing, and soft toys?

If possible, we recommend throwing out any soft materials that could be infected instead of trying to disinfect them. If you do not want to throw out infected items, you can put them in the laundry with bleach. DO NOT use accelerated hydrogen peroxide products in the laundry!

How should I clean soft surfaces like furniture or carpeting? 

You can spray any non-machine washable soft surfaces using an Accelerated Hydrogen Peroxide product. Accelerated Hydrogen Peroxide is not as harsh or irritating a bleach and should be left to air-dry on soft surfaces, with a minimum contact time of 10 minutes before rinsing or washing. It may discolor some surfaces so do a test patch before spraying the entire surface. To clean carpeted spaces, you can use a carpet cleaner or steam cleaning device. Pour some Accelerated Hydrogen Peroxide in the soap section of the cleaner and run it like you would normally, letting the carpet air dry.


Exposed cats and dogs

Do I need to worry about my own animals? 

If your resident cat(s) are fully vaccinated and up-to-date on their FVRCP vaccination, it is unlikely that they will become sick. We recommend keeping your cats separate from any sick kittens and out of any infected rooms or spaces until the two deep cleans with viral-killing products have been completed. Monitor your cats closely for any diarrhea, vomiting, decreased energy level, or other signs of illness. Most cats infected with Panleukopenia start showing signs of disease within 4-6 days of exposure, but it could take as long as 14 days for them to appear "sick." You do not need to worry about your dogs, panleukopenia only affects cats.

Fostering kittens

Fostering in the Future

When can I foster a litter of kittens?

Since panleukopenia is so hard to clean and contagious for kittens with potential deadly results, if you’ve had panleukopenia in your home, we cannot send any unvaccinated or incompletely vaccinated kittens for 6 months after your house has been cleaned. To go home with you, after your house is clean, kittens must be at least 4 months old and have at least 4 boosters of the FVRCP vaccine. You can also foster adult cats that have had at least 2 boosters of the FVRCP vaccine.

Can I foster this kitten or litter once they are better? 

Yes! Once this animal or litter has “cleared” panleukopenia at PAWS, you can take them back into your home. These kittens will have immunity to panleukopenia since their bodies have already battled the virus. We recommend cleaning your home now, before they come back into your house, and again once they have been adopted or move out of your home.

Can I foster a different kitten or litter that has already “cleared” panleukopenia? Yes! You are able to foster any kitties who have already been infected with, and cleared from panleukopenia. While cats who had an infection and have been cleared are very unlikely to catch panleukopenia again, it is technically possible, so it is really important that you remove as much of the infective panleukopenia virus as you can from your home! 


Panleukopenia is scary but many kittens survive this infection. Thorough cleaning, careful quarantine of exposed areas, and eliminating exposure risk for kittens is essential for controlling spread of the virus. While some kittens may not make it through, similar to any other severe viral infection, many kittens survive and thrive post-panleukopenia infection. Need help cleaning something unique or have other questions? Let us know!