Public health problems posed by feral cat overpopulation and an analysis of possible solutions

Feral cat overpopulation is a fact in most communities. The consequences for public health are varied and profound. There is possible transmission of rabies and other zoonotic diseases. Quality of life complaints abound, including foul odor, noise and property damage and responding to these complaints drains resources. Unchecked reproduction among feral cats results in higher cat intake and euthanasia rates (and costs) at municipal shelters.

Alternatives for addressing these consequences are: (1) do nothing, (2) feeding bans, (3) trap and remove efforts, or (4) trap/neuter/return(TNR) with rabies vaccination. Doing nothing is per se ineffective, feeding bans are usually impossible to enforce, and trap/remove efforts historically fail for many reasons, including insufficient animal control resources, resistance from cat feeders and the public, prolific reproduction, and failure to alter the habitat to prevent more cats from appearing in the future. The extreme difficulty of successful cat eradication is demonstrated by campaigns conducted on remote islands and by a recent matrix population study indicating the reduction of a feral cat population by 10% a year requires removing 50% of the cats annually.

TNR is a form of population control using sterilization, and disease management through vaccination. As a method, it has the advantages of attracting public support, private funding and volunteer labor. When properly implemented to include high sterilization rates, volunteer training, oversight, and community buy-in, TNR has reduced feral populations.