Research overview: free-roaming cat density and disease spillover risk to wildlife

The risk that domestic-cat pathogens reach wild felids and other wildlife scales with the density and distribution of free-roaming cats, especially near protected areas. This overview surveys research linking feral and outdoor cat abundance to environmental contamination with Toxoplasma oocysts and to the spillover of viral pathogens. It examines the debates around trap-neuter-return programs and whether they meaningfully reduce disease transmission, the role of supplemental feeding in concentrating cats, and the broader ecological footprint of free-roaming cats. The synthesis connects domestic cat management policy to wildlife disease outcomes. It aims to help readers appreciate that cat population density is not just an ecological or welfare issue but a direct determinant of how much pathogen pressure wild felids and ecosystems experience at the domestic-wildlife interface.