A number of factors can influence the risk of transmission of FIV between cats within a household, for example the strain of virus and/or the saliva virus load. In most situations, the risk of transmission is low in households with socially well-adapted structures. If a cat is diagnosed with a FIV infection d, all cats in that household should be tested to determine their status. FIV is mainly transmitted through biting and fighting, and if no fights occur due to the stability of social structures, FIV will probably not be transmitted In follow-up studies of households with FIV-infected cats, few additional cats ABCD Guidelines on Feline Immunodeficiency Virus 15/21 became FIV-positive over time; some households exist in which no transmission has occurred over many years. It is advisable that all cats in these households be neutered, and it is crucial not to introduce new cats, as this might lead to fights and hence transmission may occur, even between cats that have lived peacefully together for a long time.
However, if other infectious diseases are present they may be spread between cats and the risk of transmission may be higher. Therefore in that situation consideration should be given to isolating infected individuals to avoid spread of infection.
FIV is an important consideration in rescue shelters. A high prevalence of infection is found in this population of cats, particularly those with a feral background and if male and entire. The prevalence of infection may not be significantly higher in pre-owned cats that have recently been relinquished compared to the local household pet cat population, but may be higher if it is a stray cat.
ABCD panel recommend all cats should be tested, but as an absolute minimum all sick cats should be tested for FIV and in most cases euthanasia should be considered for positive cats in which the clinical problems are suspected to be related to an advanced stage of the FIV infection.
Serological tests cannot be used to reliably identify infected kittens under 6 months of age. A positive result does not confirm that the kitten is infected (see diagnosis section) and we strongly emphasise that this is not an indication for euthanasia. In this situation, PCR may be considered, although it has potential limitations.
ABCD recommends that rescue shelters should house cats individually (unless from the same household) to avoid the possibility of cross infection, but as an absolute minimum FIV positive cats should be segregated from FIV negative cats.
Some shelters will home FIV positive healthy cats to selected adopters (in situations where risk of infection to other cats is minimal) but this requires careful counselling.
FIV is rare in breeding catteries because usually the cats are kept indoors and are tested annually. New cats should be FIV tested before being introduced and cat breeders using a stud belonging to another person, or allowing a queen to visit their stud, should require proof of FIV negative status. Cats which have escaped and returned should be quarantined for 3 months, then FIV tested and found to be negative, before being returned to their group.