Feline immunodeficiency virus (FIV) is a common viral infection in cats that compromises the immune system. With appropriate care, FIV-positive cats can live long, comfortable lives — and should not be routinely euthanised on diagnosis.
FIV carries significant welfare implications in two directions: the virus itself poses a long-term health risk through immune compromise, and the diagnosis has historically led to unnecessary euthanasia of cats who could have lived comfortable lives for years. The welfare priority is accurate communication: FIV-positive cats are not immediately ill, not contagious to humans, and not necessarily contagious to other cats in well-managed household settings. Routine euthanasia at diagnosis is ethically unjustifiable when cats are clinically healthy. Welfare management focuses on preventing secondary infections through regular veterinary monitoring, prompt treatment of any illness, vaccination for other diseases (since immune defence is compromised), and maintaining the cat in a lower-stress indoor environment. Neutering of FIV-positive cats prevents both transmission through fighting and hormone-driven stress that may accelerate immune decline. Rescue organisations that adopt out FIV-positive cats as singles or pairs significantly expand their placement options and save lives.