Research overview: feline leukemia virus spillover from domestic cats to wild felids

Feline leukemia virus is fundamentally a domestic-cat pathogen, yet it has crossed into endangered wild felids with lethal consequences. This overview surveys documented and suspected spillover events, including the Iberian lynx and Florida panther outbreaks, and the conditions that promote transmission at the domestic-wild interface. It considers how feral and free-roaming cats overlapping wildcat habitat create exposure, why wild populations often lack prior immunity, and how molecular phylogenetics attributes wild infections to domestic sources. The synthesis discusses biosecurity, feral cat management and vaccination as countermeasures. It aims to explain why a single common pet virus can imperil a whole endangered species, making FeLV spillover a recurring theme in felid conservation medicine and a warning about uncontrolled domestic cat populations near vulnerable wildlife.