Dear Christopher Cat
Cleo, our 2-year-old cat, has been sick and was just diagnosed with feline leukemia.
We found her when she was about 3 months old. At that time, her leukemia test was negative. She’s always been indoors and has never been exposed to other cats.
How could she have developed feline leukemia?
We are so sorry to hear about Cleo.
It’s likely that Cleo was exposed to FeLV shortly before the earlier test was run, and that the low level of virus in her blood at that time went undetected.
Most veterinarians screen new cats for the feline leukemia virus (FeLV) using an ELISA test, a simple test that requires only a few drops of blood. This test is more sensitive and can detect the virus earlier than the other test available, an IFA test.
However, it still takes about a month from the time of exposure for the virus to multiply enough in the blood that the ELISA test can detect it.