Feline Panleukopenia

At a glance

  • About: Feline panleukopenia is a highly-contagious, life-threatening viral infection caused by the feline parvovirus.
  • Transmission: Cats become infected by exposure to infective feces, urine, saliva, via fomites (objects) such as food bowls and bedding, or during pregnancy.
  • Symptoms: Loss of appetite, bloody diarrhea, listlessness, fever, and dehydration.
  • Treatment: There are no medications to kill the virus, treatment is supportive, which may include blood transfusions, fluid therapy, nutritional support, and in some cases, antibiotics may be given.

What is feline panleukopenia?

Feline panleukopenia (feline infectious enteritis, cat plague, feline distemper, or feline parvo) is a severe and highly infectious disease caused by the feline parvovirus with a mortality rate of 25% – 70%.

In the host, it replicates in and kills rapidly dividing cells such as those lining the gut and the bone marrow resulting in a depletion of white blood cells and bacterial infection of the leaky gut wall. Cats of any age can be infected, although it is most commonly seen in kittens and feral colonies.

Feline panleukopenia virus is extremely hardy; it can withstand heating (56 C for 30 minutes) and many disinfectants and can survive in the environment for months or years.


  • Fecal-oral/urine-oral: Most commonly, cats become infected via direct exposure to infected urine, feces.
  • Direct contact: Contact with the saliva or vomit of an infected cat.
  • Vector-borne: Fleas can transmit the virus from an infected cat.
  • Indirect contact (fomites): Contact with bedding, food bowls, cages, grooming equipment, and even by a person who has been in contact with an infected cat via the hands or clothes or tracking the virus into the home on their shoes.
  • Vertical: The virus is passed from the mother to her unborn kittens.


There are two forms of infection: Fetal and Postnatal.


  • Feline panleukopenia infection in pregnant queens may result in abortion, foetal resorption, foetal mummification, and other reproductive problems. If foetuses are born alive, they usually have cerebellar hypoplasia and/or retinal dysplasia. If the mother has passed on the infection to the kittens later in her gestation, the kittens may well be born alive. They may appear well at birth or signs of ataxia (loss of coordination/clumsy motion) appear around two weeks.
  • Kittens who survive may have ataxia for the rest of their life as well as abnormalities of the retina and severe brain damage.


  • The virus infects bone marrow tissue destroying the white blood cells (leukopenia) making the cat vulnerable to secondary bacterial infections.
  • The virus attacks rapidly diving cells in the lining of the gut (epithelium) leading to ulceration and eventually destruction of the epithelium, which causes bloody diarrhea, which is a common symptom.
  • Attacks rapidly dividing cells in the nervous system.
  • Severe and untreated dehydration can lead to shock and death.


The incubation period can range from 2 – 14 days, but symptoms usually occur within around a week of exposure. Symptoms vary from cat to cat and range from mild to severe. The onset of symptoms appears rapidly, and owners may mistake the onset of this infection for poisoning.

  • Loss of appetite
  • Hypersalivation (drooling)
  • Lethargy
  • Abdominal pain
  • Vomiting
  • Bloody diarrhea

Infected cats may hang off their food or water bowl, they often have a hunched-up appearance and their coat quickly becomes unkempt. The skin loses its elasticity due to dehydration caused by vomiting and diarrhea.

Cats at the terminal stage may have a subnormal temperature, convulsions, and lapse into a coma. Death usually follows within hours.

Death usually occurs within the first five days, and cats who survive past five or so days will usually pull through.


Your veterinarian will give your cat a physical examination, take a history of your cat (ie: has your cat been vaccinated/exposure, etc.), check for clinical signs, and quite possibly perform a blood test to see if the white blood cell count is down.

Physical findings:

  • Dehydration (prolonged skin tenting)
  • Sunken eyes
  • Pallor
  • Rapid breathing (tachypnea)
  • Rapid heart rate (tachycardia)
  • Low body temperature (hypothermia) or fever
  • Prolonged capillary refill time
  • Drooling
  • Poor pulse time
  • Hypovolemic shock
  • Shortness of breath (dyspnea)

Diagnostic workup:

  • Baseline tests: Complete blood count,  blood smear, biochemical profile, and urinalysis. The CBC and blood smear may reveal leukopenia (low white blood cells).
  • Blood gas: A test to measure the amount of gasses (oxygen and carbon dioxide) and acid-base pH levels in the blood. A small amount of blood is drawn from an arterial blood supply and placed in a blood gas analyser.
  • Antigen test: A fecal test to detect parvovirus antigen.
  • Polymerase chain reaction: If the fecal antigen is negative, but the veterinarian still suspects panleukopenia. This test amplifies small segments of viral DNA.
  • Imaging: Ultrasound if intussusception is suspected


The prognosis for kittens is poor, especially in younger kittens. In one study, factors that influence survival rates included:

  • The weight of the cat at the time of hospital admission: The risk of death decreases for every 1 kg of bodyweight
  • Rectal temperature: Each 1°C increase in rectal temperature at admission, the risk of death decreased by 31%
  • Lethargy: 91% of cats with lethargy ad the time of admission died

There are no medications that can kill the virus; treatment is aimed towards fluid therapy, nutritional support, antibiotics, gastrointestinal support, and supportive care. The goals should be focused on the three H’s:

  • Hypovolemia/hydration
  • Hypothermia
  • Hypoglycemia

Antibodies usually appear within around 3 – 4 days of infection, so if the cat can be kept alive for this long, hopefully, the antibodies will be able to fight off the infection. Two days later, there is a sharp rebound in the white blood cell count.

  • Blood transfusions if the white blood cell count drops significantly
  • Antibiotics to fight off secondary bacterial infections which can develop due to decreased white blood cells
  • Anti-viral medications (omega-interferon)
  • Intravenous fluids to correct dehydration and electrolyte imbalances
  • Painkillers
  • Antiemetics to control vomiting
  • Vitamin B and C injections
  • Nutritional support (feeding tube)
  • Plenty of tender loving care is important as cats can lose their will to live


The virus can survive for a very long time in the environment. The following disinfectants are effective against panleukopenia. Organic material inactivates many detergents, so it is important to clean the area with detergent before disinfection.

  • Bleach (sodium hypochlorite, calcium hypochlorite, or sodium dichloroisocyanurate)
  • Trifectant or Virkon-Potassium peroxomonosulfate
  • Virox, Accel – Accelerated hydrogen peroxide
  • TriGene-Didecyl dimethyl ammonium chloride, benzalkonium chloride, polyhexanide (biguanide)


The best way to prevent panleukopenia is to vaccinate your cat, which is 99% effective.

If you have had an outbreak of feline panleukopenia, careful management of the environment is extremely important. The virus is extremely hardy and careful disinfection of food bowls, bedding, utensils, etc., with bleach, will help reduce the viral load.

Is panleukopenia contagious to humans?

No, feline panleukopenia can infect members of the Felidae family, Mustelidae (mink and ferrets), but it doesn’t infect humans.


  • Julia Wilson, 'Cat World' Founder

    Julia Wilson is the founder of Cat-World, and has researched and written over 1,000 articles about cats. She is a cat expert with over 20 years of experience writing about a wide range of cat topics, with a special interest in cat health, welfare and preventative care. Julia lives in Sydney with her family, four cats and two dogs. Full author bio

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