Study: TNR reduces feline euthanasia, overpopulation

Veterinarians from the study are pictured performing spays and neuters on "community" cats from a targeted area in Gainesville, Florida. Photo courtesy of University of Florida.Funded by a $250,000 grant from Maddie's Fund, a foundation dedicated to research and education to further "no-kill" solutions, the University of Florida (UF) feline trap-neuter-return (TNR) program, Operation Catnip, found that a targeted approach helped effectively manage the feral cat population and reduce shelter euthanasia rates in that area. While executing the program on a larger scale may be cost prohibitive, study results show that at the community level the method was a success.

The two-year study, published in The Veterinary Journal and run by principal investigator Julie Levy, DVM, PhD, the Maddie's Fund professor of shelter medicine at the UF College of Veterinary Medicine, focused its TNR efforts to a region of Alachua County. The five-square-mile area is adjacent to the UF campus and includes the downtown Gainesville business district, several residential neighborhoods, a mobile home park, two homeless shelters, industrial parks and a veterinary clinic. According to the UF release, the area has higher unemployment and poverty levels as well as lower household income and rates of home ownership than the county as a whole.

By performing a random-digit telephone survey of the target area, Levy and her team found that 11 percent of families fed an average of 4.3 unowned feral or stray cats each, usually on the property where they lived or worked. With data that indicated feeding "community" cats was a common activity in the area, the team collaborated with residents to trap unowned cats for neutering. "We provided traps, carriers and free transportation to the clinic for the cats," Levy says. "Most of the cats were captured by residents, but our team also did some trapping when residents were not available or were unable to carry it out themselves."

Study participants neutered 2,366 stray and feral cats, estimated to be 54 percent of the feral cat population in that area. As a result, Levy reported a 70 percent decline of animal control cat intake from a baseline of 13 cats per 1,000 residents to four cats per 1,000 residents at the end of the study. Outside the target area, the county saw only a 13 percent decrease in animal control intake.

According to the study results, euthanasia declined 95 percent, from a baseline of eight cats per 1,000 residents to less than one per 1,000 residents. Euthanasia rates dropped 30 percent in the surrounding nontarget area.

In addition, Levy says the adoptions they saw during the program were as incredible as the results. “Adoption wasn't part of the original plan, but it happened organically as residents offered to take in kittens and the friendlier adults,” she says. The study also noted that shelter intake of dogs declined in the targeted area as well. Levy's team talked to community members about how to care for their animals and resources available for their pets.

In all, 1,169 cats were returned to their colonies, 61 cats were relocated to other colonies, 308 cats were adopted in the target area and 805 were transferred to pet rescue groups for adoption.

However, Levy admits when the program began cats didn't arrive in large numbers as the team had expected. “They were out there, but this is a community that doesn't just take stray cats to a spay-neuter clinic,” she says. Levy hired a neighborhood resident to knock on doors and find out what the community needed to participate.

“It's not enough for an agency like ours to just make services available. You must get into a community and talk to people to find out what they need,” Levy says. “If we go in with the right resources and attitudes, we can save animals from animal control and from being euthanized."

“The animal welfare community as a whole has realized that we can't be solely shelter-centric,” she continues. “The next step in our work is to connect with communities, find out their needs and how we can help.”

Levy does acknowledge the financial limitations of expanding this approach to a larger area. “It's not realistic to provide this level of coverage throughout the community in an untargeted way. To expand what we did in the target area to the entire county would cost millions of dollars,” she says. “But like all daunting problems, you bite off the greatest need and start there.”

The TNR debate

The execution of the University of Florida study comes at a time of great debate in the state-as in many communities across the country-on the effectiveness of TNR to control the population of approximately 50 million feral cats in the United States. Last May, pro-TNR groups including Alley Cat Allies supported state legislation in Florida (House Bill 1121 and Senate Bill 1320) to define feral cats as "community" cats and stipulate that the practice of TNR does not constitute abandonment or unlawful release of cats. The legislation died in committee, but set off a firestorm of debate among various groups. Opponents of the bills called keeping feral colonies legalized hoarding, a threat to public health and an endangerment to the welfare of feral cats.

The Hillsborough Animal Health Foundation (HAHF), of which Don Thompson, JD, CVPM, president and owner of Veterinary Center at Fishhawk in Lithia, Fla., is executive director, and his wife, Katie Thompson, DVM, DABVP (canine and feline), is a member, opposed the community cat legislation.

The foundation, founded in 1987 by Tampa-area veterinarians, states on its website that there are no studies that prove TNR is effective in reducing the feral cat population. “Taking on TNR isn't a popular position,” Don Thompson concedes. “But in the end, we've got to come up with another solution.”

As an alternative, the foundation has developed a program called “AWAKE,” which it believes is more effective than TNR. AWAKE stands for “Animal Welfare, Adoption, Kids and Education.” Its method is to trap, evaluate, neuter, vaccinate, adopt and contain. Supporters believe cats belong indoors or contained to prevent the risk of zoonotic disease, specifically rabies, toxplasmosis, intestinal parasite infection and bartonellosis. AWAKE opponents believe an attempt to contain feral cats is unattainable and the program, doomed to fail.

Tufts University also went against traditional TNR with a 2013 computer model study that rapidly compared the predicted efficacy of vasectomy and hysterectomy (TVHR) versus neutering. During the course of the 6,000-day simulated cat population model, TVHR reduced the population by half with an annual capture rate of 35 percent. With TNR, to reduce the population by a quarter, 57 percent of the cats in a colony had to be removed by lethal means or captured, neutered and released.

Tufts researchers found that with a 35 percent TVHR rate, the colony could be completely eliminated within 11 years. The capture rate would have to reach 82 percent for the colony to be eliminated by TNR in 11 years.

Levy contends that the TVHR approach has not been tried in the "real world" and it does not factor in community concerns about unowned cats such as spraying and fighting, nor the welfare of the cats themselves. "Cats that still have raging hormones with hysterectomy/vasectomy continue to be a nuisance, live shorter lives, and contract more infectious diseases," she says. For those reasons, Levy chose to use the traditional spay/neuter approach she says eliminates hormones and makes cats healthier and easier to share our community with.

"Our previous research has shown that TNR reduces cat colony size over time and that some colonies are even permanently eliminated," Levy says. "Our new study also showed that TNR can be effective over a large area and that residents can be recruited to help manage the cat population humanely while reducing the reliance on tax-funded animal control shelters."

Regardless of the ongoing debate, Levy says trap-neuter-return continues to be the most common method of population control in Florida, and a majority of urban animal control shelters in the state now offer TNR services.