Feline panleukopenia virus (FPV) is a highly contagious viral infection that affects cats. While rare in fully vaccinated pet cats, FPV remains a serious concern in shelters and multi-cat environments, where many cats are unvaccinated or recently rescued. FPV targets rapidly dividing cells in the intestines, bone marrow, and immune system, which can lead to severe illness or death, particularly in kittens under 5 months old.
Vaccination, isolation, and environmental hygiene are key to preventing the spread of this virus in both shelters and homes.
Why is FPV dangerous?
FPV is a non-enveloped, single-stranded DNA virus that can survive in the environment for up to a year. It spreads mainly through fecal-oral transmission, making contaminated surfaces, food, water, or contact with infected cats a serious risk.
The virus attacks:
- Rapidly dividing intestinal cells → vomiting, diarrhea, and gastrointestinal damage
- Bone marrow → low white blood cell counts and increased risk of secondary infections
- Lymphoid tissues → weakened immune system
Kittens, unvaccinated cats, and immunocompromised cats are at the highest risk.
How do cats get FPV?
Cats can become infected by:
- Contact with infected feces or vomit
- Contaminated bedding, food bowls, or litter boxes
- Interaction with infected cats
Because FPV is hardy, proper cleaning with strong disinfectants (bleach, peracetic acid, sodium hydroxide) is critical in shelters and multi-cat households.
What are the signs of FPV infection?
Symptoms usually appear within a few days of infection:
Early signs:
- Lethargy
- Loss of appetite
- Fever
- Vomiting
- Diarrhea
Advanced signs:
- Severe dehydration
- Weakness or collapse
- Sudden death in severe cases
Because symptoms overlap with other illnesses, any young or unvaccinated cat with these signs should be evaluated promptly.
How is FPV diagnosed?
Diagnosis may include:
- Fecal snap tests – quick, reliable if positive; negative results may need confirmation
- PCR testing – more sensitive, done on feces, vomit, or anal swabs
- Presumptive diagnosis – in shelters, treatment often begins based on clinical signs to prevent spread
How is FPV treated?
There is no cure for FPV, so treatment is supportive:
- IV fluids for dehydration
- Nutritional support
- Antibiotics to prevent secondary infections
- Medications to control vomiting and pain
Early treatment improves survival, particularly for kittens.
How can shelters prevent FPV outbreaks?
Preventing FPV is critical in shelters:
- Vaccination: Shelter kittens are vaccinated starting at 4 weeks old, boosted every 2 weeks until 16–20 weeks. Adult cats are also vaccinated.
- Isolation: Infected or exposed cats must be separated from healthy cats.
- Environmental cleaning: Disinfect non-porous surfaces with bleach, peracetic acid, or sodium hydroxide.
- Foster programs: Temporary housing for healthy cats reduces exposure.
- Trap-Neuter-Release (TNR) programs: Vaccinating stray cats protects both feral and pet populations.
What is the prognosis?
Survival depends on:
- Age and immune status
- Speed of supportive care
- Severity of infection
Kittens under 5 months have the highest risk. With prompt care, many cats recover, but severe cases can be fatal.
Why is vaccination for FPV important?
Vaccination is the most effective way to prevent FPV. Vaccinated cats are less likely to develop severe disease and less likely to spread the virus. Keeping vaccines up to date protects both individual cats and the wider community.
Acknowledgment
This FAQ was developed using information from the senior paper of Breckan Waite (’26 DVM), “Feline Panleukopenia Virus in Animal Shelters,” submitted October 31, 2024, under the guidance of Dr. Cassidy Cordon.
This information is not meant to be a substitute for veterinary care. Always follow the instructions provided by your veterinarian. Washington State University assumes no liability for injury to you or your pet incurred by following these descriptions or procedures.