Feline Retroviruses

July 27, 2014 / Cat's Meow / Leave a comment


Cats, just like people, can be infected with retroviruses. These viruses are masters of disguise that can remain hidden for many years before causing obvious disease. As such, testing and prevention is crucial to ensure the health of our feline companions. There are two main retroviruses that affect domestic cats:

Feline Immunodeficiency Virus (FIV)

This disease is related to HIV (the virus that causes AIDS), but can only infect cats. Cats can get FIV from their mother at birth, but are usually infected via bite wounds from fighting with other cats. For this reason, intact males are most commonly infected, though any cat is at risk. Overall in North America, ~5% of cats test positive for FIV. Cats in stable households can live with FIV+ cats for many years with a low risk of infection.

Tom, an FIV+ cat, lives with Dr Kornya and his two FIV- kitties


Cats with FIV may experience a brief period of flu-like symptoms, and then have months to years without any overt clinical signs. Some cats will eventually enter a “feline-AIDS” stage later in life when they become very prone to infections, cancers, and other diseases. Even before entering this stage, FIV+ cats are more likely to have dental disease and upper respiratory infections, and may be slower to heal and recover from illness.

Though historically FIV has been seen as a fatal disease, recent evidence suggests that many cats can live normal lives with proper care and management. There is no effective vaccine for FIV, and treatment is generally based on managing symptoms, as anti-retrovirals are expensive and not well tolerated in cats.

Feline Leukemia Virus (FeLV)

Despite its name, FeLV causes a wide range of diseases in cats including many types of cancer, anemia, and immune system suppression. Cats get infected through mutual grooming, sharing water bowls, mating, and at birth. Any cat can be infected, and cats sharing a home with infected cats are at high risk of disease. In North America ~3.5% of cats are infected.

Cats that are positive for FeLV can have months to years of no symptoms, much like FIV. They are also more prone to dental disease and slow healing. After this phase, they begin to show clinical signs which are rapidly fatal. Treatment is symptomatic, and there is no cure.

There is an effective vaccine available for FeLV, which the American Society of Feline Practitioners (AAFP) recommends cats receives at least once, as a kitten, followed by additional vaccines for high-risk animals. Vaccination has had a major role in reducing the amount of FeLV in the past decades, and FeLV associated disease is more rare today than it has ever been. Vaccinating your cat can help the effort to eradicate it forever.

Retrovirus Testing: A fast and simple test is available for both FIV and FeLV. It requires a small blood sample and can be run in-house, results take about 8 minutes. The test is very accurate, though some people may wish to confirm a positive result. The AAFP (and Village Cat Clinic) recommend all kittens be tested, as well as any new additions to your household.

Please come by the clinic and talk to us about feline retrovirus testing and prevention options.

Written by Dr Matthew Kornya

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