The trap-neuter-return process aims to gradually reduce stray cat populations while also allowing the cats to continue living in the outdoors they've made homes.

You’ve seen that friendly kitty wandering around your neighborhood. Maybe you put out food and water for her and say hello each morning. Heck, maybe you have your own Abraham de Lacy Giuseppe Casey Thomas O’Malley living nearby. 

They’re likely not alone. Depending on where you live, your nearby colony of feral or stray cats could span from just a few felines to dozens of them. According to the American Society for the Prevention of Cruelty to Animals (ASPCA), there could be tens of millions of community cats across the United States. 

“There are cats everywhere,” says Megan Wiedmann, the trap-neuter-return coordinator for the Animal Rescue League of Iowa

Everywhere includes Des Moines, Iowa. As of late July 2020, the ARL’s trap-neuter-return (TNR) program has spayed or neutered more than 920 cats in Iowa’s biggest city over a year and a half. Cities and counties across the country employ or allow TNR programs, including in large cities like San Francisco, Chicago, and New York City. In Georgia, the LifeLine Animal Project has spayed or neutered more than 35,000 stray and feral cats in more than 21 counties around Atlanta.

Over several years, these programs hope to curb the community cat population—and cut down on cat-related complaints—while allowing the cats currently living there to live healthy, full lives.  

What is TNR?

Short for trap-neuter-return, it’s exactly what it sounds like. Under Des Moines’ TNR program, residents can humanely trap their community cats and then take them to a veterinarian or the ARL where they’ll be spayed or neutered and vaccinated. After the procedures, the Des Moines TNR cats are microchipped before they’re returned to their colonies’ areas where they can resume their lives. 

“They already know where their hiding spots are, where their food is,” Wiedmann says. 

While the cats are still under anesthesia, the vet also "ear-tips" them by clipping off a few centimeters of the cat's left ear. It doesn't hurt the cat, and serves as a signal to humans both that the cat lives outside and that he's been neutered, perhaps saving it a trip to the shelter.

The idea behind the practice is to gradually reduce the overpopulation of community cats by preventing them from reproducing. According to the Zimmer Feline Foundation, unaltered community cats produce 80 percent of all kittens born each year, which creates a continual cycle of overpopulation. Feral cats are a far cry from the domesticated felines who have homes to call their own. These cats live short, often painful lives: Without veterinary care or regular access to food, water, and shelter, they can run a higher risk for contagious diseases, parasites, and other conditions that go left untreated.

Finding, trapping, and altering the cats takes time and resources, Wiedmann says, but it’s better than the alternative: euthanizing. And that might not even reduce the cat population. It does nothing to stop remaining cats from reproducing, replacing the euthanized cats with new kittens.

Euthanizing also costs big bucks. LifeLine estimates that trapping and euthanizing thousands of feral cats in the Atlanta area can cost about $3.5 million annually. A healthy TNR program can prevent those costs for taxpayer-funded animal shelters.

Because cats live for years, it takes awhile for cat welfare groups to see the population numbers drop. The ARL has spayed and neutered more than 900 cats since 2019, but there are likely somewhere between 10,000-14,000 feral, stray, and community cats living in Des Moines. 

“We’ve only made a small dent,” Weidmann says. 

The goal for most TNR programs is to spay or neuter about 80–85 percent of the community cats in their areas, Wiedmann says.

However, not all animal groups are on board with TNR. Some, like the American Bird Conservancy, say TNR programs don’t reduce cat populations if the vast majority of the cats aren’t altered. Plus, feral cats—regardless of their ability to reproduce—will still prey on small mammals, birds, and other native wildlife.  

group of stray cats outside
Credit: Benjamin Egerland / EyeEm / Getty

Benefits for TNR Cats (and People)

Unneutered male cats will fight, putting themselves at risk to transmit diseases through their bites and scratches, Wiedmann says. Neutered cats no longer look for mates, and the procedure also cuts down on their testosterone levels, hopefully resulting in less fighting and disease transmission.

The prevention of loud fights is also a benefit for people living nearby. Female cats in heat are noisy as well, Wiedmann says, so an effective TNR program can improve the quality of life around cat colonies. 

Alley Cat Allies, a stray and feral cat advocacy group, says female cats’ health will improve without the stress of repeated mating and pregnancy while neutered cats will see their coat condition improve and weight gain. 

Disease prevention is another plus. In Des Moines, the ARL will vaccinate the cats it spays or neuters for rabies and feline distemper, which helps protect the other cats in the colony and residential pets who might venture outside. 

Weidmann says the goal is to “try and make them as healthy as possible.” Given the stress caused by mating and from birthing endless litters of kittens, it's an effort that many rescue organizations are willing to take on. 

Managing a Cat Colony

You may be living near or in a cat colony without even knowing it, especially if the cats there are feral. Feral cats mostly stay out of site until it’s dark out. 

Colonies can exist in rural or urban areas. On farms, the cats might come to hunt the rodents who are there to eat livestock feed. In cities, dumpsters full of food or a friendly neighbor who puts out provisions might be the basis for a colony. (Perhaps you sense a common theme: food availability.) 

To effectively manage a colony, the Zimmer Foundation recommends establishing a feeding schedule for the cats, conditioning them to come to a certain area at a certain time. That sets the groundwork to eventually trap them so they can be spayed or neutered and then returned. 

If you’ve managed to sterilize the entire colony, you should still keep an eye on it for newcomers. 

Those are the best practices, so here’s what not to do, according to the ASPCA. Eradicating the cats—whether through relocation or euthanizing a colony—doesn’t work. 

Removing the cats will create a “vacuum effect.” The absence of cats in an area that's suitable for them—meaning there's readily available food, water, and shelter—will simply attract different cats to come take up residence. (Hello, ready-made shelters and food to eat!) That’s why Alley Cat Allies says catching and killing is not only cruel but pointless. 

It’s a similar story for relocating cats. Either new ones will replace the cats who were removed, or the cats will find their way back to their territory because they’re so connected to it. Cats should only be relocated if staying in the area could hurt or kill them, the ASPCA says.

Adopting any community cats into homes, reversing course after an entire life spent outside, probably won’t work either. Is it possible? Sure, but it can take years for the cat to acclimate to living inside. Alley Cat Allies says that for every successful feral cat adoption story, there are 20 stories of feral cats who miserable after being brought inside.