Portrait of a cute tabby cat.

Feline Leukemia

Feline leukemia is a viral infection that can result in immunosuppression, decreased white blood cell count, neoplasia, and, in some cases, neurologic dysfunction. It is common in the United States, affecting 2-3% of all cats.

Who Is at Risk?

It is most common in high volume situations (such as shelters) where infection status may be unknown, and in cats that are indoor/outdoor or primarily outdoor, where they are most at risk of being bitten by an infected cat. Kittens are more at risk than adult cats.

How Is Leukemia Transmitted?

Leukemia is mainly transmitted through saliva. It can also be shed in the urine, feces, or nasal secretions of affected cats. Transmission can occur during grooming between cats, through bite wounds, or, less commonly, through the sharing of items in the household (bowls, litter boxes, and toys). Placenta transmission from mother to kitten has been reported as well.

How Is it Diagnosed?

The virus is diagnosed via a SNAP test, which only requires a few drops of blood. The test can be run in minutes at your primary care veterinarian’s office.

This is an ELISA test. If this initial test shows up positive, your veterinarian may send out for additional testing to confirm active FeLV infection.

How Are Symptoms of FeLV Presented in a Cat?

What Should You Do If Your Cat Has FeLV?

What Is the Long-Term Prognosis?

Cats with FeLV can have a normal lifespan and live long, healthy lives. If they develop secondary conditions (such as anemia), the prognosis becomes more guarded. We recommend that cats who are FeLV-positive visit their veterinarian more regularly (every 6 months as opposed to annually).
If you have a cat who is considered high risk (primarily outdoor), we recommend getting the FeLV vaccine. Talk to your veterinarian and see if this vaccine would be beneficial for your cat.

FeLV is a viral infection of cats. In the early stages, infected cats may show no symptoms at all. FeLV is linked to serious diseases, most notably cancer and anemia. If your cat is high risk, it is important to get them tested annually.

Depending on time of diagnosis and overall health of the cat, patients with FeLV can live active, normal lives. Keeping them inside and making more frequent trips to the veterinarian will help the cat’s prognosis.