Feline Immunodeficiency Virus is caused by a virus that is related to the human HIV virus that causes AIDS. FIV is, therefore, also called cat AIDS. FIV can only infect the cat and not humans. It is not a zoonosis! The virus is transmitted through blood contact. Cats are mainly infected through fighting and bite wounds. Because males fight much more often, the percentage of infected males is twice as high as infected females.
The disease is most common among healthy domestic cats, which go outside. Cats that live indoors, in a group where the ranking is determined, will not infect each other easily, because they don’t fight much with each other. Mating is also often bitten (neck bite), so the male can infect a female cat. A pregnant female cat can also transmit the disease to her kittens via the placenta and later on via her mother’s milk. In FIV, the main transmission occurs much more through a direct bite wound with fighting and to a much lesser extent through prolonged social contact. FeLV, on the other hand, is mainly transmitted by prolonged social contact and, to a much lesser extent, by a bite wound with fighting.