The Feline Immunodeficiency Virus (FIV) is spread worldwide. Like nearly all lentiviruses FIV also occurs mainly cell-associated and is only infectious in the outside world for a short period. Transmission takes place by parenteral inoculation of virus-containing cells in the bloodstream of a healthy cat. Nearly 100% transfer probability is given through a bite from an infected cat. It should be noted that antibody formation begins only after two weeks, initially with the appearance of env-specific, then with gag-specific antibodies.

The Feline Leukemia Virus (FeLV) causes the widespread feline leukemia virus infection, which is still one of the leading causes of death in cats. The incubation period varies from animal to animal. In some cats the first symptoms can be seen after a few days of infection, while in other animals it takes weeks, months or years. The retroviruses are transmitted versatile, e.g. through saliva, nasal secretions and urine, hence they represent a high risk of infection to other cats. If the virus infects the bone marrow, the blood formation will get disturbed which leads to anemia and leukemia. The feline leukemia virus (FeLV) is widespread in the feline population and usually fatal, there is a very high risk of infection.

You can vaccinate against the Feline Leukemia Virus, whereas a vaccination against the feline Immunodeficiency Virus is not yet available everywhere. To diagnose an infection of FIV or FeLV solely on the basis of clinical symptoms is very difficult. A mixed infection of FeLV and FIV accelerates the progression of a FIV infection.

Because of similar clinical symptoms in suspected cases, a combined screening test is recommended, such as the Fassisi FeLFIV, which can detect both pathogens individually with only one rapid test device. Especially cats who live in uncontrolled housekeepings with lots of fellow species and cats with free outlet belong to the risk groups. A combined indirect pathogen detection of FIV antibodies together with direct antigen detection (FeLV antigen) can be performed reliably in practice.