At Nutmeg, we can test your cat or kitten for feline leukemia or feline AIDS via a quick, in-house blood test. Click here for an details on the Feline AIDS virus.

Feline leukemia virus, a retrovirus, is a common infection of cats. It is the cause of more cat deaths, directly or indirectly, than any other organism and is widespread in the cat population.

Disease Transmission

Feline leukemia virus infection (FeLV) can be transmitted:

  1. by the saliva of infected cats contaminating the eye, mouth, and nose membranes of non-infected cats via licking.
  2. by passing infected blood to non-infected cats.
  3. from mother to fetuses (developing kittens) during pregnancy.


Most infected cats eliminate the virus and become immune. In those cats that do not develop immunity, the virus spreads to the bone marrow. A large percentage of the cats that are exposed to the virus will have latent (hidden) infections and will be capable of transmitting the disease in saliva, tears, and urine. Some of these latent carriers will become clinically ill when stressed.


There is no effective treatment for the bone marrow form of leukemia. Treatment is mainly supportive, and may require blood transfusions, prednisone, and anabolic steroids. FeLV cancer (lymphoma) has a better response to therapy than the bone marrow diseases do. Treatment may include chemotherapy, glucocorticoids, interferon, Protein A, and supportive treatment.


Eighty-five percent of cats with FeLV infection die within 3 years of the diagnosis.

Prevention of FeLV

There are several preventive measures that can be taken to decrease the risk of contracting FeLV.

  1. Nutmeg Clinic does not provide Feline Leukemia vaccine; please refer to your own veterinarian for advice. Cats are most vulnerable to the virus as kittens. Kittens may be tested at any age, however, infection in newborn kittens may not be detected until weeks to months after birth. Therefore, several FeLV tests during the first six months of life may be necessary to feel completely "safe" about a negative test result.
  2. Vaccinate your adult cat after testing negative for FeLV.
  3. Keep your cat indoors and do not allow exposure to untested and unvaccinated cats.