A new study shows that over a 10-year period, free-roaming cat populations managed by a high-intensity trap-neuter-return (TNR) program experienced 31 times fewer preventable cat deaths than when no action at all was taken.
A Long-Term Lens: Cumulative Impacts of Free-Roaming Cat Management Strategy and Intensity on Preventable Cat Mortalities was recently published in the peer-reviewed open-access journal Frontiers in Veterinary Science. The research was funded in part by the ASPCA.
Using sophisticated modeling software to simulate the impacts and associated costs of seven different management strategies on reducing cat populations, the study’s key findings include:
- TNR can be effective for reducing preventable deaths. When performed effectively, TNR can reduce preventable deaths drastically while also reducing population size.
- Intensity matters. The ability of TNR to reduce preventable deaths and population size largely disappears when implemented at lower levels (sterilizing 25% of cats every six months, as compared to 75%).
- Kitten mortality deserves more attention. Kitten deaths comprise a large majority of preventable deaths under all management scenarios, including removal where trapped cats are euthanized.
- Reducing abandonment is important. More than with any other option, TNR outcomes (especially population size reduction) can be improved by efforts to reduce abandonment and adopt out friendly cats.
- Comparing approaches. Culling (waiting until populations reach a certain level before removing and euthanizing cats) is likely to be ineffective for population management regardless of intensity, while the effectiveness of regular removal (a certain percentage of cats removed every six months) varies with intensity.
“Sadly, many communities still opt to do nothing to control populations of community cats or use outdated, ineffective methods such as sporadic trapping and removal. This research confirms that high-intensity TNR is the most effective, humane way to stabilize a population of community cats and, over time, reduce them,” said Margaret Slater, DVM, PhD, Senior Director of Research at the ASPCA and co-author of the study.
"This research confirms that high-intensity TNR is the most effective, humane way to stabilize a population of community cats and, over time, reduce them.”
According to Dr. John Boone, wildlife biologist and ACC&D Board Vice Chair, “The effectiveness of TNR programs often is debated, but less commonly is defined well. TNR groups most often track numbers of sterilizations performed and cats entering or euthanized in shelters as measures of effectiveness. These metrics are important, but they do not measure reduction in numbers of outdoor cats or illustrate how management translates into ‘lives saved’ in an outdoor cat population.”
This study is a joint effort by experts in cat welfare, wildlife conservation and veterinary medicine. Participating authors came from the Alliance for Contraception in Cats & Dogs (ACC&D), the ASPCA® (American Society for the Prevention of Cruelty to Animals), Great Basin Bird Observatory, Illinois State Museum, International Union for Conservation of Nature - Conservation Planning Specialist Group (CPSG) and University of Florida College of Veterinary Medicine. ACC&D coordinated this study with several phases of the work funded by a grant from the ASPCA.