Photo: Flickr/Sara Golemon
Feral cat colonies: They're the worst, right? They spread mind-altering parasites, help kill off small mammals and birds by the billion, and are the inspiration for sub-par Disney movies. Many of the cats meet poor fates, dying of hunger, disease, or injuries.
The general strategy to reducing these colonies have been trap-neuter-release programs, which is exactly what it sounds like: Cats are neutered or spayed and returned to the streets, the hope being that the colony will eventually die off naturally. But according to a new study out of Tufts University, that strategy only works with small colonies.
A new strategy, one where cats are given a vasectomy or hysterectomy and then released, could be much more effective. That's because a neutered cat loses all of its sex hormones, making it unlikely to get into alley cat fights with unneutered cats that stumble along. One with a vasectomy retains its reproductive hormones, meaning its "life span, sexual drive and social status aren't altered," according to Michael Reed, one of the authors of the study, published in the Journal of the American Veterinary Medical Association.
"He'll fend off competing males who try to intrude into his area even though he can't actually produce offspring," he said.
A similar thing happens with female cats who get hysterectomies. They'll still try to mate and will enter a 45-day "pseudo-pregnancy period," which can also dissuade fertile males from entering the colony.
In the United States alone, there are roughly 70 million feral cats. Both feral and regular ol' housecats have been blamed for helping 33 different species go extinct. The Smithsonian Conservation Biology Institute has said they are the single biggest threat to American wildlife.
Using a computer model, which I assume was called "Sim Alleycat," Reed and his colleague Robert McCarthy found that the vasectomy method was much more effective than trap-neuter-release programs.
“The computer model indicates that vasectomy and hysterectomy should be much more effective at reducing or eliminating feral cat populations than the traditional approach of neutering," McCarthy said. "The next step is to gather evidence on how it actually works in the field.”
In order to make the population of a feral cat colony fall by a quarter, more than half of the cats had to be killed or trapped-neutered-and released. Using the vasectomy method, colonies were reduced by half within a year if just 35 percent of the cats were treated. Within 11 years, the colony was completely eliminated. Using trap-neuter-release, more than 80 percent of cats had to be treated.
"Although altering feral cats prevents future generations from suffering, it does not protect cats from the litany of other problems that they may encounter. Allowing feral cats to continue their daily struggle for survival in a hostile environment is rarely a humane option," it said.
The organization says it can be "marginally acceptable" to catch-and-release cats when they are "isolated from roads, people, and animals who could harm them, are regularly attended to by people who not only feed them but also provide them with veterinary care, and are kept in areas where they do not have access to wildlife and the weather is temperate." At which point, are they really feral anymore?
Others, such as Alley Cat Allies, has said that catch-and-release programs are "humane and effective" and are better than catch-and-kill programs. Either way, it's better than what Texas does to feral hogs.