Three Years, Six Shelters, 72,970 Cats: The TNVR Impact

The crisis of overcrowded animal shelters in the United States is essentially common knowledge; many people, animal rights advocates or otherwise, are aware that millions of cats and dogs are euthanized annually due to uncontrolled populations and limited resources.

Cat advocates have been working for decades to find methods to help curb this problem, and trap-neuter-vaccinate-return (TNVR) has emerged as a popular humane method to manage community cat—including stray and/or feral —populations. While popular, the method’s impacts on animal shelter population and euthanasia rates had yet to be carefully measured over a long period of time, until recently.

To help fill this crucial data gap, researchers have come forward with the present study to determine exactly how TNVR is making a difference. The researchers were interested in two versions of TNVR: high-impact targeting and return-to-field (RTF), both of which have been developed over the past decade.

The targeting approach focuses TNVR efforts in specific areas that are recognized to have larger populations of community cats, often evidenced by higher cat intake rates at shelters. The RTF method is primarily applied for individual cats. These cats have been designated as “strays” and are not necessarily part of a larger community cat colony. Shelters typically launch community cat programs (CCPs), concerted efforts to reduce community cat populations, that make use of both methods. Additionally, the researchers were interested in the “red-flag cat model” hypothesis, which states that an area with one community cat is probably also home to other cats that are unsterilized and free-roaming. This hypothesis helps inform targeting TNVR.

The study took place over three years and included data from municipal shelters in Albuquerque, New Mexico; San Antonio, Texas; Baltimore, Maryland; Philadelphia, Pennsylvania; Tucson, Arizona; and Columbus, Georgia. Each shelter launched a CCP with both targeted and RTF methods, with deliberate targeting in areas that were recognized as producing many cat intakes. Shelters recorded the number of cats sterilized as well as how many were returned to their location and how many were adopted. To identify the effects of the CCPs on the shelters, all of the numbers were compared to the same data points from the year preceding the study.

Over the three-year study period and across the six different shelters, 72,970 cats were sterilized in total. Of these, 79% were a result of targeted TNVR while the other 21% were from RTF methods. While 83% of the cats were returned to their original trapped location, 15% were adopted or transferred to a private rescue (the remaining cats died, were euthanized due to illness, or released without surgery). In total, the CCPs were executed across 12,912 individual sites.

As for the shelter numbers, the data are encouraging. At the end of the three-year programs, overall cat euthanasia at all shelters decreased by a median rate of 83%, with kitten euthanasia decreasing by a median of 87%. Cat intake dropped by a median of 32% and kitten intake a median of 40%.

TNVR’s effects on adoption rates is not as definitive, with cat adoption rates dropping by 82% in Columbus and increasing by 118% in San Antonio. However, measuring the cat adoption rates as a proportion of cat intake reveals a median increase of 45% at all but the Baltimore shelter.

Additionally, the red-flag cat model hypothesis was supported by this study. 1,817 red flag cats led to the TNVRing of 15,658 cats, or 22% of all cats who were part of the CCPs. On average, about four cats went through a CCP for each red-flag cat.

There are several positive takeaways from this research. First, that euthanasia decreased by a median of 83% across shelters is incredible, considering that these shelters each serve communities with varying populations, demographics, and geographies. This supports the universality of TNVR programs. Further, all of the shelters saw decreases in the number of cats and kittens being brought in, and decreased kitten intake supports the effectiveness of TNVR at reducing cats’ reproductive capacities. The researchers attribute these intake decreases to the integrated use of both targeted and RTF methods of TNVR. Finally, this study demonstrated support for the hypothesis of the red-flag cat model. This changes the implication of seeing a single community cat in your neighborhood: now, you would be wise to assume that there are others running around too.

One concern of TNVR skeptics is that community cats’ lives are fraught with disease, starvation, violence, and other tragedies that make it cruel to allow their free-roaming to continue post-sterilization. However, out of all of the community cats who went through the CCPs of this study, only .5% required euthanasia due to a critical health condition and .2% died while in the shelter’s care. The remaining community cats were, overall, in quite good health.

An interesting fact taken from the article’s introduction is that the U.S. has no legislation regarding the population management of community cats. With the shelter situation as dire as it is, this places the bulk of the burden upon the shoulders of community members and organizations. It’s important that, as both animal advocates and members of our communities, we enact policies that prioritize the wellbeing of animals while simultaneously controlling their populations. Studies such as this demonstrate that TNVR is a reliable method worthy of serious consideration for both the issues of community cat overpopulation and shelter overcrowding.

You could also see TNVR as another way to support your local animal shelter: fewer cats in intake means there is less strain on resources and the system. This, in turn, can translate into greater operational efficiency when shelter employees and volunteers feel less stressed and experience less compassion fatigue.

For both the sake of the animals and for us, it’s critical that we focus efforts into methods with well-documented success. Now, we have broader quantifiable data that show just what kind of impact TNVR can have.