Immunofluorescence Assay Testing for Feline Leukemia

Feline leukemia (FeLV) is one of the leading causes of death in cats. This disease can cause cancer, but it also weakens the immune system, allowing other diseases to easily develop. Once the virus enters the cat's body, there are three possible outcomes, all about equally probable. It's possible that the virus will be destroyed within 12 weeks by antibodies created by the immune system. In this case, the cat is not longer infected, and no longer contagious. It's also possible that the antibodies created will partially, but not completely, destroy the virus. In this case, the virus remains latent in the bone marrow and T-cells. Common cancer and other diseases may not develop, but the virus can be re-activated under stressful conditions. If the antibodies do not destroy the virus, the cat will develop feline leukemia and likely die in a year or less.

Testing for Feline Leukemia

There are two tests which will help to determine whether or not feline leukemia is present in your cat, and can simultaneously detect the feline immunodeficiency virus as well. The ELISA will likely be the first of the two tests performed, and this test can usually be administered and interpreted at your veterinarian's office. Since the ELISA can give a false positive reading, any cat testing positive for feline leukemia will be a candidate for the second test.

Immunofluorescence Assay (IFA)

The immunofluorescence assay, commonly shortened to IFA, is a more thorough test for determining feline leukemia in cats. Once the ELISA has come back positive, the IFA will be administered. Like the ELISA, the immunofluorescence assay is a test that uses a blood or bone marrow sample to detect the presence of antibodies to the virus. Since the IFA gives a more precise reading, results will be determined by an outside laboratory. Results can usually be determined in a matter of days.

Preventing the Spread of Feline Leukemia

Feline leukemia is a contagious virus. This virus can be spread among cats easily by saliva, eating from the same dish, using the same litter box, fighting, grooming or nursing. It can even be passed when two cats simply touch noses. Once a cat has either been positively identified (even in the case of a false positive) or diagnosed with feline leukemia, it is highly recommended to quarantine the cat. Keeping the cat inside and away from other cats in the household is of utmost importance. Any cats exposed to, or living in the same house with an infected cat should be tested immediately for the virus, and retested again after a 30-day period.

Other Considerations

When dealing with a potential feline leukemia infection, and facing definitive testing like the immunofluorescence assay, there are other notable and possible concerns. FeLV vaccinations do not interfere with the results of the IFA test. A positive result can be determined whether or not vaccination has been performed in the past. Additionally, treatment of FeLV is generally directed at keeping the cat as healthy as possible to prevent other life-threatening bacteria and diseases. Care should be taken to research the best diets, and prevention of stress and exposure to other cat illness.