Feline Panleukopenia (Parvo in Cats)

Feline panleukopenia, also known as feline distemper, feline parvovirus, or “parvo”, is a highly contagious disease caused by infection with feline parvovirus.  Various strains of feline parvovirus exist around the world and infection occurs in both domestic and wild cats.

What is Feline Panleukopenia?

Feline panleukopenia is a highly contagious and often fatal disease caused by feline parvovirus.  Kittens are most susceptible to infection with feline parvovirus, but any unvaccinated cat can be infected.  The virus attacks rapidly dividing cells in the bone marrow, lymphoid tissues, and intestine.  In very young animals, rapidly dividing cells in the cerebellum (brain) and retina are also affected.  Infected cats experience a decrease in white blood cells (panleukopenia), which affects their ability to fight infection.

How Do Cats Get Parvo?

Infected cats shed parvovirus in their body secretions, particularly in their feces.  Transmission primarily occurs via the fecal-oral route, which means cats must ingest infected feces to become infected.  This can happen through contaminated food or water, sharing litter boxes with an infected cat, direct contact with an infected cat, or by the transmission of virus particles on objects such as shoes or clothing.  Parvovirus is very hardy and can live in the environment for long periods of time – up to a year under the right conditions – so cats can become infected without ever coming into contact with an infected cat.  Transmission can also occur in utero from a mother cat to her kittens.

Can Cats Get Parvo From Dogs?

Yes, cats can get parvo from dogs.  Canine parvovirus can infect cats and cause disease.  Vaccinating cats for feline parvovirus protects them against canine parvovirus as well.  Feline parvovirus can infect dogs, but it does not cause disease in dogs.

Can Humans Get Parvo From Cats?

Humans have their own type of parvovirus, called parvovirus B19.  Humans cannot get parvovirus from cats, and cats cannot get parvovirus from humans.  However, humans can transmit parvo from cat to cat by carrying the virus on their clothes or skin.

Signs of Parvo in Cats

Adult cats infected with parvovirus may have a subclinical infection, which means they may not become ill from the virus.  Cats that do become clinically ill are usually less than one year old.  In cats that do become ill, acute disease is most common, and sudden death is possible.

Signs of parvo in cats include:

• Depression
• Anorexia
• Vomiting
• Diarrhea
• Fever initially, followed by hypothermia
• Crouched body position
• Abdominal pain
• Dehydration
• Abortion
• Stillbirth
• Infertility

Kittens infected with feline panleukopenia in utero or during the neonatal period typically display neurologic signs by 10-14 days of age.   Signs of feline panleukopenia in young kittens include:

• Clumsiness
• Wide-based stance
• Incoordination
• Elevated, rudder-shaped tail
• Intention tremors of the head
• Seizures
• Abnormal behaviors
• Blindness

Diagnosing Feline Parvovirus

To diagnose feline parvovirus in your cat, your veterinarian may recommend some or all of the following tests:

• Physical Examination. Your veterinarian will perform a comprehensive head-to-tail physical examination on your cat.  Your veterinarian will also ask you questions about your cat’s history such as your cat’s symptoms, vaccination history, and recent exposure to other cats.
• Blood Work. A complete blood count and biochemistry panel are typically recommended to diagnose feline panleukopenia.  Decreased white blood cell counts – known medically as panleukopenia – are a common finding with this disease.  Biochemistry results can be variable and may include dehydration, electrolyte imbalances, and hypoalbuminemia.
• Fecal Antigen Test. Your veterinarian may recommend using a sample of your cat’s feces to test for feline parvovirus antigen, which can be used to diagnose a feline parvovirus infection.  False positives are possible up to two weeks after vaccination for feline panleukopenia.
• PCR Test. Your veterinarian may recommend a PCR test to look for feline parvovirus.  This test is commonly performed by a laboratory and can be performed on whole blood, bone marrow, fecal, or tissue samples.

Feline Parvovirus Treatment

Unfortunately, there is no specific treatment for feline parvovirus.  Treatment for parvo in cats is supportive care while the virus runs its course.

Feline parvovirus treatment may include:

• Fluid Therapy. Fluid therapy is necessary to correct dehydration and electrolyte imbalances.  Fluid therapy may be administered intravenously (IV), subcutaneously (SQ), or intraosseously (IO) depending on the needs of the patient.
• Anti-emetics. Anti-emetic medications such as maropitant or metoclopramide may be administered to control vomiting. These medications may be given orally (PO), subcutaneously (SQ), or intravenously (IV).
• Nutritional Support.  A bland highly digestible diet is often offered.  In some cases, a feeding tube may need to be placed to ensure the patient continues to receive adequate caloric intake.
• Antibiotics.  Parvovirus attacks cells of the intestinal tract, leading to bacterial translocation into the bloodstream.  Broad-spectrum antibiotics may be used to counteract bacteremia.
• Transfusions.  Some patients with severe anemia and protein loss may require whole blood or plasma transfusions, respectively.

Can a Cat Survive Parvo?

Feline parvovirus is fatal for many cats.  However, the prognosis for recovery is good if the cat survives the first few days of illness.  Kittens with cerebellar hypoplasia can have a good quality of life depending on the severity of their neurologic deficits, though many will need special accommodations.

Feline Panleukopenia Vaccine

Fortunately, parvo in cats is preventable through vaccination.  Feline panleukopenia is a core vaccine for cats, which means all cats should receive this vaccine.  Vaccination for feline panleukopenia typically begins when a kitten is 6-8 weeks of age.  The vaccination is then boostered every 2-4 weeks until the kitten reaches 16-20 weeks of age.  Adult cats should have their feline panleukopenia vaccine boostered either annually or triennially depending on the manufacturer’s recommendations. Your veterinarian will determine the best vaccination schedule for your cat based on your cat’s age, previous vaccination history, and health status.

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