Feline Panleukopenia Virus (Distemper) in Cats

Key Takeaways

Feline Panleukopenia (FPV), also known as distemper, is a highly contagious viral infection in cats. 

• FPV transmission is through direct or indirect contact with fecal particles from infected cats

• Cats with FPV present in various ways depending on the age of presentation, with symptoms ranging from vomiting, diarrhea, and severe immune suppression in older cats to sudden death in kittens

• Diagnosis of FPV involves physical examination and laboratory testing such as fecal antigen detection

• Treatment of FPV includes supportive care, anti-nausea medications, and medications to protect the gastrointestinal tract

• Prognosis is poor with a mortality rate of 25-75%. Kittens under 3 weeks old have a 90% mortality rate 

Given the extremely high mortality rate combined with the effectiveness of vaccination, FPV is one of the pathogens included in all start of life and ongoing vaccination protocols for pets.

A Closer Look: What is Feline Panleukemia Virus in Cats?

The symptoms of FPV vary widely depending on the age of onset.

• Infection of a fetus during the first 21 days of gestation can lead to abortion.

• Fetal infection after 21 days of gestation leads to cerebellar hypoplasia, due to the virus targeting the rapidly dividing cells in the brain. Kittens born with cerebellar hypoplasia show symptoms such as uncoordinated movement (ataxia) and seizures. These kittens often have life-long neurologic deficits. 

• Kittens infected under three weeks of age dcan develop cerebellar hypoplasia, with ataxia and seizures, or die suddenly. 

• Older kittens/adult cats typically develop gastrointestinal disease or immune system depletion with symptoms such as diarrhea, vomiting, fever, lethargy, and pale gums.

Risk Factors

FPV is a serious, highly contagious condition with a high mortality rate. Cats showing symptoms of FPV require emergency veterinary treatment. Vaccination is highly effective and readily available. Clinical disease in vaccinated animals is very rare.

Cats that contract FPV should be isolated from other cats. Any surfaces exposed to positive cats are infectious for a year after the last confirmed case. Bleach is an effective disinfectant against FPV, however many surfaces (such as porous surfaces or soil) may not be adequately cleaned. Therefore, any new cats introduced to the environment must be current on FPV vaccination to prevent infection.

Possible Causes

FPV is shed in the feces of infected cats. The virus is stable in the environment for up to a year. Most transmission to cats occurs through contacting contaminated objects, rather than direct contact between animals. Once a cat is infected, the virus primarily targets the gastrointestinal tract and the immune system, causing serious, life-threatening disease.

Main Symptoms

The most common symptoms of FPV in cats include:

DiarrheaVomitingLethargy • Poor appetite • FeverPale gums

Testing and Diagnosis

Investigation of FPV includes:

• Physical examination • Blood work • Laboratory testing - demonstration of viral antigen in the feces

Steps to Recovery

Treatment of FPV focuses on supportive treatment, including:

• Fluid therapy • Correction of electrolyte and glucose imbalances • Anti-nausea medications

• Assisted feeding to maintain nutrition • Antibiotics to prevent secondary bacterial infections

• Medications to protect the gastrointestinal tract • Blood transfusions

Medication to enhance the immune response to FPV may be trialed, although their efficacy has not been proven

The prognosis for FPV infection is poor. 25-75% of cases are fatal, despite supportive care in hospital. Cats that recover often show reduced or resolved symptoms within 5-7 days. Most cats surviving gastrointestinal or immune system disease have minimal long-term effects after recovery. 

Infection in kittens less than 3 weeks old are fatal in 90% of cases. Cases that survive often result in lifelong disability such as ataxia, due to malformation of the cerebellum.


FPV is highly contagious and is spread readily between unvaccinated cats.

Vaccination is effective at preventing transmission and symptoms of FPV. Most vaccination protocols recommend vaccination at 6 weeks, then every 3-4 weeks until 16-20 weeks of age. After completing the kitten vaccines, a booster is administered at 1 year, then every 3 years for the remainder of life.

Is Feline Panleukemia Virus Common in Cats?

Widespread vaccination means that FPV is rare. Most cases of  FPV are found in groups of unvaccinated cats.

Typical Treatment

Treatment of FPV involves:

• Supportive care • Treatment of secondary bacterial infections • Medication to enhance to viral immune response

Want to speak to a vet now?

Book an appointment

Health concern with your pet?

Start a video chat with a licensed veterinary professional right now on Vetster!

Book an online vet

Online veterinarian and virtual pet care services available on-demand.

Available now on Apple and Play stores.

Vet on phone