Research overview: declining FeLV prevalence over time

Large serosurveys document a substantial decline in FeLV prevalence across many countries since the 1980s, attributed to testing, vaccination, removal of infected cats from breeding and group settings, and increased indoor housing. Despite this success, the virus persists, with higher prevalence in free-roaming, sick, and male cats, and pockets of higher burden in regions with less access to veterinary care. This overview synthesizes epidemiologic surveys rather than a single source, describing the drivers behind the long-term decline, why prevalence varies sharply by population and geography, and why ongoing testing remains important even as overall numbers fall. It matters because FeLV control demonstrates how coordinated prevention can reshape the burden of an infectious disease in companion animals.