Feline Immunodeficiency Virus - Testing

Testing

Veterinarians will check a cat's history, look for clinical signs, and possibly administer a blood test for FIV antibodies. FIV affects 2-3% of cats in the US and testing is readily available. It should be noted that this testing identifies those cats that carry the FIV antibody, and does not detect the actual virus.

False positives occur when the cat carries the antibody (which is harmless), but does not carry the actual virus. The most frequent occurrence of this is when kittens are tested after ingesting the antibodies from mother's milk, and when testing cats that have been previously vaccinated for FIV. For this reason, neither kittens under 8 weeks nor cats that have been previously vaccinated are tested.

Kittens and young cats that test positive for the FIV antibody may test negative at a later time due to seroreversion, provided they have never been infected with FIV and have never been immunized with the FIV vaccine.

Cats that have been vaccinated will test positive for the FIV antibody for the rest of their life due to seroconversion, even though they are not infected. Therefore, testing of strays or adopted cats is inconclusive, since it is impossible to know whether or not they have been vaccinated in the past. For these reasons, a positive FIV antibody test by itself should never be used as a criterion for euthanasia.

Tests can be performed in a vet's office with results in minutes, allowing for quick consultation. Early detection helps maintain the cat's health and prevents spreading infection to other cats. With proper care, infected cats can live long and healthy lives.