Should your cat have a feline leukemia test done?
Feline leukemia is a disease that can strike fear into the hearts of any loving cat owner. There are a number of strains of the disease and there is a feline leukemia test that can diagnose all three types of the virus, but it can not tell the difference between them.
There are two FeLV blood tests that are used. These are Enzyme-linked immunosorbent Assay (ELISA) and Immunofluorescent Assay (IFA).
The ELISA test finds antigens in the cat’s blood serum, while the IFA finds antigens in the white blood cells.
ELISA can detect the early stages of the disease, while the virus is still in the blood and hasn’t yet progressed to the bone marrow and white blood cells. Unfortunately, this test is prone to false positive results. It can test using the cat's saliva and tears, but is said to be unreliable.
Kittens with positive test results from ELISA should be retested again when they are 16 weeks of age or older.
Uninfected kittens can test positive if they are carrying their mother’s antigens, though by 16 weeks of age the antigens should be out of the kitten’s system. This generally means that the cat has developed immunity and will not likely become infected.
With IFA testing, cats are considered positive for life. A negative result does not mean the cat is uninfected. This can occur in cats that are infected, but were exposed only a short time before, and haven't developed any antibodies.
An infected cat's blood may show: