Feline Immunodeficiency Virus (FIV) is one of the most common infectious diseases found in cats. They most commonly become infected by being bitten by another infected cat while fighting. However, the virus can also be transmitted through sexual contact and very rarely, from mother to kitten if the mother has been recently infected. It is unlikely to be transmitted from casual contact (sharing food bowls, snuggling, etc.). Infection can occur at any age.
Cats or kittens that become infected may show vague signs of illness as soon as six weeks after infection, such as enlarged lymph nodes or fever. These signs can last days to months before the virus goes into a dormant period. This period can last several years, until the immune system becomes weakened and secondary infections often occur.
Infected, symptomatic cats will often have a fever and a low number of white blood cells. They may also have eye disease as well as neurologic symptoms such as seizures and behavior changes. They are more likely to develop neoplasia (cancer) and are prone to other infectious diseases due to their weakened immune system.
Cats can go for years without showing any signs and are able to infect other cats during this time, this is why testing is key. Your veterinarian will use a small blood sample to perform this in-house test. If your cat tests positive, you will need to take a few precautions, particularly if you have other cats.
FIV positive cats should be indoor-only cats so that they will be less likely to infect other cats. Indoor-only cats do not need to be separated from non-infected cats unless they are prone to fighting. Vaccination is generally not recommended as the vaccine causes antibody production, which will cause a false positive on the test. Therefore, the FIV vaccine is only recommended in high-risk cats (colonies, etc.).
All cats and kittens should be tested during their first veterinary visit. Young kittens should be re-tested after six months of age as maternal antibodies may cause a positive result before this period. Any cat that has recently been in a fight could have potentially been exposed and should be tested. Any sick cat with signs of neurologic disease, white blood cell abnormalities, or stomatitis should also be tested.
FIV positive cats can enjoy nice, happy, long lives if provided with a healthy, low-stress home environment.