Spaying Cats In One Shot

Feral cats live a rough life, and programs like Trap, Neuter, Release (TNR) attempt to keep their populations from exploding in a humane way. Researchers in Massachusetts have found a non-surgical way to spay cats that will help these efforts.

A single dose of anti-Müllerian hormone (AMH) gene therapy suppresses ovarian follicle formation, essentially turning off the ovulation cycle. After following the test cats for two years, none had kittens, unlike the cats in the control group. Other major hormones like estrogen were unaffected in the cats and they didn’t exhibit any negative side effects. The researchers said it will be some time before the treatment can be widely deployed, but it offers hope for helping our internet overlords and the environs they terrorize inhabit.

For those of you doing TNR work, you might want to try this trap alert system to let you know you’ve caught a cat for spaying or neutering. If you’d rather use a cat treat dispenser to motivate your code monkeys, then check out this hack.

61 thoughts on “Spaying Cats In One Shot

    1. That is bollocks cats are not to blame for the massive loss of birds…they only get the weak ..those figures of blame were based on ground birds where Europeans brought dogs cats and rats ro island wherebthere were nonpredators before
      It’s pesticides loss io habitat ..hunting shooting g galleries…humans with guns

      Planes that don’t respect or investigate bird flight paths …(plane strike )
      People idiots allowed to buy rodent poison and scatter it everywhere against the correct way if being g dor a targeted species ..(in a trap)

      1. You are ill-informed regarding “shooting galleries”. Songbirds are not a target for any hunters. Pest bird species, such as the Big Three in the US (European Starling, English House Sparrows, and Collared Doves) are all identified by the US Govt as invasive species, and have no limit on eradication except where explicitly prohibited- IE: bird sanctuaries”.

        Pesticides do play a major role. I’ll grant you that.

        But claiming cats “are not responsible” contradicts research by the American Bird Conservancy. I personally have seen a major disruption in 5 states I’ve lived in since the early 90s encompassing the 4 corners of the US plus mid-Eastern seaboard, plus interactions with other avian abatement specialists through the country.

        And if you try to cite the UK/EU studies, I’ll point you in the direction of Australia just to further stifle any claims you make.

        1. I find this very interesting, since you both make plausible arguments.

          Considering domesticated cats have been in all of North America for over a century, why would they only start disrupting bird populations in the 90s? What changed?

          1. Higher cat population, but also confirmation bias. People have started to care about this way more now and are noticing the impact more.

            For figures, by the way, here’s a Nature article: It’s about 1.3-4.0 billion birds and 6.3-22 billion small animals a year in the US alone, mostly due to feral domesticated cats. The phrase they use is ‘likely the single greatest source of anthropogenic mortality for US birds and mammals’.

          2. Because domestic outdoor cats get too fat and lazy to hunt by age 2. I changed mine’s name from BabaYaga to Cartman.

            Ferals are the real killers. A fat lazy outdoor cat protects birds by keeping the feral cats out of his territory.

      2. It’s industrial poisons. Enormous plumes of Atrazine, Flupyradifurone, Hexachlorobenzene, Glyphosate, Methomyl, and Rotenone. It’s not kitty cats and certainly not uh.. guns.

        Which is way darker. We can’t stop using that stuff without a billion people or so starving. Will world-managers decide to use this gene therapy sometime in the future on humans to reduce that risk? People don’t like to think about it, but history says yes they probably will.

        1. ” Will world-managers decide to use this gene therapy sometime in the future on humans to reduce that risk?”

          Bill Gates denies that the vaccines he supplies to Africa have any such ingredients.

      3. By weak, do you mean fledgling? I shouldn’t be bothered by all the dead things my neighbor’s cats leave at my front door? The baby bluebird a few weeks ago.
        Piss off with your toxoplasmosis addled brain!

  1. Tens of thousands of women in the united states have been sterilized against their will, often secretly.
    The idea that they *wouldn’t* use this technology against humans is absurd.

    Furthermore, with gene editing, it is likely practical to make a persons offspring sterile, instead of the person treated. This of course opens the door to even more subtle and horrifying tactics.

      1. Can’t tell if you’re being sarcastic.

        Look up the Tuskegee Syphilis Experiment. Some incredibly unethical things have been done in the name of advancing medical science.

    1. If you follow the link, you’ll see this treatment came out of efforts to maintain fertility in human cancer patients. Any technology can be used against people by a motivated aggressor, but that doesn’t mean we shouldn’t use it when it has obvious beneficial applications, IMO.

      Many countries have sterilized people of any sex for political reasons, but that’s a problem of politics, not tech.

      1. A new tech making it much easier and possible to do without immediate detection will change the political calculus that determines if an idea is merely considered or acted upon.

      1. As I ask of all those who promote conspiratorial allegations in this vein, who is “they”? Can you document their existence? And verify their actual impact, if they exist.

        it’s not an unreasonable question.


  2. This is fantastic news! I think people are hung up on the fact that this was used on felines. When given a broader perspective, you can see this could be the first step in actually making a realistic plan for removing the many invasive species that are doing real harm.

      1. While a certain subset of humans is responsible for most of our current ecological woes, we’re also at the point where it’s going to take humans to clean up the mess to minimize the loss of biodiversity. Biodiversity flourishes in areas where people have stewarded the land.

        By some estimates, 80% of the world’s biodiversity is maintained by indigenous cultures, for example:

          1. Yep. But it wouldn’t be a crisis as there wouldn’t be a paranoid human to call it a ‘crisis’ . Just adapt to the new weather patterns for the time period in question :) and go on with life.

  3. without knowing any details, superficially it sounds like if the cat’s hormones are unaffected and it is merely sterilized then it seems like the cat would still go into heat? if i understand correctly, i think this general technique is more potent than regular sterilization, because the cat will consume (fruitlessly) mating resources from non-sterilized cats. iirc the same approach is being used against some mosquitos, with hopes of an actual genocide. (i’m tentatively in favor, fwiw)

    1. It sounds like there might be decreased prevalence of the cat going into heat, but that it depends on the cat? Probably need a larger sample size before you’d know for sure since there were only six treated cats, but 4/6 didn’t allow breeding during the trials. From the paper: ““Dolly” (low-dose group) allowed six breeding bouts during the first trial and three breeding bouts during the second. “Barbara” (high-dose group) allowed one breeding bout during each trial. No luteal phases were detected in fecal hormone analyses following any of the bouts (Table 1). No breeding behavior was observed from the other four treated females.”

  4. If you want to get rid of pest animals, what’s the point of sterilizing them? Just trap, poison or shoot them.

    It’s hypocritical and false morality to be killing an animal, but being all “humane” about it by letting nature do the dirty deed. The same cats will probably die by getting hit by a car, mauled by a dog, parasites, starvation, frozen to death…

    1. What “humane” seems to mean in this context is not that the animal shouldn’t suffer needlessly, but that the person killing the animal should not feel guilty or have their public image tainted over the fact.

    2. TNR tends to be practiced by people who like cats, but want to mitigate the impacts of the feral population on the environment with the eventual goal of getting feral cat populations to zero in areas where they are invasive. Also, as you said, feral life is rough, so preventing more cats from having to live that way is part of why one would use the humane moniker.

      Most ferals aren’t amenable to adoption by humans, but we still want them to be able to live out their natural lives, even if outdoor cats (feral or otherwise) have a significantly shorter lifespan than their indoor counterparts. The Wikipedia article has a fair bit more on the pros/cons of the practice:

      1. >preventing more cats from having to live that way is part of why one would use the humane moniker

        There’s several problems with that statement, depending on how you look at it.
        1) what about this one cat you’re sterilizing? If you want it gone anyways, wouldn’t it be more humane just to kill it now?
        2) Genocide is humane when it is used to reduce the suffering of an unwanted group? Animals don’t have human rights, but the logic of it is still fishy.

    3. “If you want to get rid of pest animals, what’s the point of sterilizing them? Just trap, poison or shoot them.”

      Sterilization, theoretically, is more effective than lethal control: if you just kill the animals, all it does is basically just leave space in the niche open for other animals to fill it, whereas if you sterilize animals, it allows you to basically stabilize the population where you have fewer animals to deal with (because it’s only the “new” ones – if you kill them, they’re always new).

      The problem is that it’s a difficult situation – there’ve been deer population studies where female sterilization didn’t actually help because the fawns were replaced by adult males who were drawn to the area since the females were constantly in estrus.

      1. > leave space in the niche open for other animals to fill it

        But it has the same effect, just with a slight delay. Reducing births opens up the niche just the same. If the intent is to remove the cats from the area, then it’s going to happen anyways.

        1. You’ll never get rid of them all, no matter how easy you think it is.

          The best you can do is keep the population small, which includes the local spayed population defending its turf and keeping out others.

    4. Cats are territorial. You would rather have sterile cats keeping out more feral cats that will have 5-20 more kittens.

      Also if you eradicate cats you will be overrun by rats and mice.

    1. Probably never, but the cats have TERRIBLE lawyers, so nothing will ever come of it.

      (Non-sarcastic reply: there’s ALWAYS paperwork, and plenty of it, to ensure an animal study minimizes the suffering of animal subjects. I don’t THINK we’re very close to requiring “consent” from animals, but things do change over time.)

  5. Do they still go into heat?

    That’s an important question, because being in heat is a massive source of stress for the animal, _especially_ if conception doesn’t occur — we’re talking about shorter lifespan, higher risk of various diseases, etc. I’ve even seen studies that female cats who’ve been neutered in ways that don’t stop them going into heat can suffer from mental problems. i.e. they’re wired to expect kittens, but the kittens never come, and after a while they just go kinda weird. But I can’t find a reference for that now.

    If they do still go into heat, then this would be a really bad choice for pets. OTOH it might be useful for controlling the wild population of feral cats, which is an environmental disaster.

  6. For what it’s worth, contraceptive implants were tried on female cats in the early 1980s (we had one in the family treated through some friends in the local vet school). They worked wonderfully, saving the cat the trauma of surgery and without side effects (though with cats you never can quite tell). The difference is that it was an ongoing implant that dissolved over time rather than permanent suppression of ovulation, but the concept is hardly new.

  7. You had it correct when you write terrorise, at least for down here in Australia.
    Cats kill 360 million birds a year and have pushed many of our unique animals to extinction.
    Yet folks here still argue against keeping their cats inside. They let emotion override data at the expense of natural ecosystems, and politicians won’t tackle it as it’ll cost them votes. It’s a bloody tragedy.

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