Thursday, April 18, 2024



HomeNational Animal NewsZoo Researchers Discover Way To Sterilize Cats Without Surgery

Zoo Researchers Discover Way To Sterilize Cats Without Surgery

Cincinnati, OH – Researchers with the Cincinnati Zoo have developed a way to sterilize cats without putting them through surgery. A news release outlines details of the ground-breaking study which has huge implications for controlling the overpopulation of cats.

The study, funded by The Joanie Bernard Foundation and The Michelson Found Animals Foundation, demonstrates how Anti-Mullerian Hormone (AMH) gene therapy can effectively sterilize female cats, reducing the need to put them under anesthesia for spay surgeries.

Senior author and CREW’s Director of Animal Research, Dr. Bill Swanson (DVM, PhD) commented on the limitations of traditional spay surgeries to control feline populations:

“The trap, neuter [spay], return model is difficult to achieve on a large scale because surgery requires general anesthesia, an adequately equipped surgical facility, and more veterinarians than are currently available,”

The study included six female cats at the Conservation and Research of Endangered Wildlife (CREW) who were treated with AMH gene therapy and three untreated female cats who served as controls. One injection of the treatment caused the cats’ muscle cells to produce AMH and raised the overall level of the hormone by approximately 100 times the normal amount produced by the ovaries.

Two-month breeding trials were performed one and two years after the treatment. Dr. Lindsey Vansandt (DVM, PhD), the lead author on the paper and CREW director of the Imperiled Cat Signature Project, said:

 “Evidence for the effectiveness of this treatment is strong. All of the control (non-treated) cats produced kittens, but none of the cats treated with the gene therapy became pregnant.”

The cats who were treated were tested and monitored for more than three years and there were no adverse effects observed, indicating that the gene therapy was “safe and well tolerated.”

Gary K. Michelson (MD), founder and co-chair of the Michelson Found Animals Foundation, which helped fund the study, commented on the gene therapy’s potential impact:

“A non-surgical sterilant for community and companion animals is long overdue and will transform animal welfare. This breakthrough discovery is a major milestone in our quest to provide pet owners with an alternative to surgical spay and neuter.”

All of the cats involved in the study were made available for adoption at the conclusion of the research, with many of them finding homes with zoo staff and volunteers. Dr. Swanson adopted three, stating:

“We are cat lovers, which is one of the reasons we’re excited about what this new technology can do to improve the lives of domestic cats,”


Read more about this breakthrough research here.

non surgical neutering cats


Continue reading: Adorable dog hops shelter wall to get to friend

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  1. Excellent! This could be a breakthrough for cats in colonies on the streets. Education and low cost spay/neuter clinics with a lot of outreach and TNR are still necessary and while I am not sure how much of a difference this would make for them, I am happy that new ways of helping them are being developed. Progress is not always so good but in many instances it is.

  2. This is a good news but it will be better and easier if it was a pill I can mix with food because there are to many feral cats, and is not easy to trap them

  3. I know a presumably one-time injection sounds “easier” on the surface than a surgery, but I think in the long run it would make it much more difficult for colony caretakers, because with traditional TNR, the cats get an eartip which identifies them as having been spay/neutered. Cats receiving injections aren’t being put under anesthesia, so they won’t get eartipped. In feral cat colonies, there tend to be a lot of cats who look similar to each other, because they’re all related to each other, and without an eartip, it would be terribly difficult if not impossible for the caretaker to keep track of which cats have and haven’t been “fixed”. Also, if feral cats get trapped, sterilized with an injection, receive no eartip, and then at some point in the future after being released back to their colony, any of them get trapped again by someone else who isn’t going to be able to tell the cat has been “fixed” already, if the cats then get a traditional spay/neuter, great, but what happens if a cat who’s already received a sterilization injection receives another one? What effect is that going to have on the cats? Also, when the cat’s ovaries and uterus aren’t being removed, in favor of giving the cat an injection to sterilize her, things will still be able to go wrong with the cat’s unused “equipment” that could shorten her life.

  4. They can just put a little earring clamp on the cat’s ear to indicate it was spayed/neutered. This injection is a game changer!

  5. If this could work, it’d be wonderful!! It is so hard to get the stray cat population under control. We take care of a colony, You TNR 6 kittens, 1 cat has 4 more…never ending.



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