Feline immunodeficiency virus (FIV) is a Lentivirus that affects cats worldwide by compromising their immune system, with 2.5% to 4.4% of felines being infected.
FIV and HIV are both lentiviruses. However, humans cannot be infected by FIV, nor can cats be infected by HIV.
FIV is transmitted primarily through deep bite wounds, where the virus present in the infected cat’s saliva enters the body tissues of another cat. FIV+ cats can share water bowls, pellet bowls, eat from the same bowl of wet food, and use the same litter box with low danger of transmitting the disease.
A vigilant pet owner who treats secondary infections can allow an infected cat to live a reasonably long life. The chance that an FIV-infected cat will pass the virus to other cats within a household is low, unless there is fighting between cats, or wounds present that could allow entry of the virus from infected to non-infected cat.
Newborn kittens may test positive for up to six months and most thereafter will gradually test negative. It is thought that this is due to antibodies transferred to the kittens via the mother’s milk. However these antibodies are transient so subsequent testing will be negative.