Research overview: comparative pathogenicity of feline immunodeficiency virus across felid species

Feline immunodeficiency virus causes an AIDS-like syndrome in domestic cats yet has long been assumed benign in its wild hosts. This overview examines the evidence for and against that assumption, comparing how FIV affects domestic cats, lions, pumas and other felids. It reviews immunological studies finding subtle T-cell perturbations in infected wild lions, debates over whether long co-evolution selects for tolerance, and the possibility that FIV imposes sublethal costs that matter only alongside co-infections or stress. The synthesis considers why pathogenicity might differ across host-virus pairs and what this means for endangered species harboring their own endemic lentiviruses. The aim is to move readers beyond the simple benign-versus-deadly dichotomy toward a nuanced view of lentivirus disease in the cat family.