New contraceptive injection could help manage stray cat populations

Scientists have developed a single-dose contraceptive for female cats that shows promising results that will last a lifetime.

The breakthrough was developed by scientists at the Cincinnati Zoo & Botanical Garden in Ohio, who aimed to cost-effectively control the world’s 480 million population of feral or stray cats.

Treatment includes anti-Müller hormone (AMH), which connects to receptors in the ovary and helps regulate ovulation.

The injection is administered into the thigh muscle of the animal while they are awake and could be used on other animal species in the future.

An estimated 480 million domestic cats around the world are feral or stray, with anywhere from 30 to 80 million free-roaming cats struggling on their own in the United States.

The stray animals face a tough life themselves and often end up with euthanasia in an animal shelter.

To make matters worse, these cunning and hungry savage hunters are responsible for decimating endangered bird, reptile and small mammal species around the world.

But researchers have found a more practical solution than costly and failed surgical sterilization efforts: a new long-term contraceptive injection for felines.

“We are cat lovers,” said one of the study’s co-authors, Dr. Bill Swanson, a director of animal research at the Cincinnati Zoo & Botanical Garden, “which is one of the reasons we’re excited about what this new technology can do to improve the lives of domestic cats.”

“The fall, neuter [spay]”Model of recurrence,” said Dr. Swanson, “is difficult to achieve on a large scale because surgery requires general anaesthesia, an adequately equipped surgical facility and more vets than are currently available.”

Swanson and his team’s solution, as published in the last issue of the magazine Nature communicationis a single dose of anti-Müller hormone (AMH) gene therapy, which they have found prevents ovulation in queens over a long period of time.

Six female cats at the Cincinnati Zoo & Botanical Garden’s Center for Conservation and Research of Endangered Wildlife (CREW) were treated with the long-term contraceptive shot.

In addition to those six felines dosed with the contraceptive AMH gene therapy, three untreated females served as a control group.

The researchers hope to ease the tension caused by the estimated 480 million domesticated cats around the world who are feral or stray. Six kitties at the Cincinnati Zoo & Botanical Garden (above) were treated with the long-term birth control shot

After three years, when the study was a success, all nine of the study cats were eligible for adoption. Dr. Swanson took three of the lab cats home herself

“The evidence for the effectiveness of this treatment is strong,” said the study’s lead author, Dr. Lindsey Vansandt, director of CREW’s Imperiled Cat Signature Project.

‘All control [non-treated] cats gave birth to kittens, but none of the cats treated with the gene therapy got pregnant,” she said.

AMH gene therapy works by prompting the cat’s muscle cells to produce AMH, which is typically produced only in the ovaries.

A single injection of the treatment increases the presence of the hormone in cats about 100 times.

The high concentration of AMH serves as a contraceptive by suppressing the production of follicles in the ovaries in cats and other mammals.

Following the success of the CREW team’s two-four-month breeding trials, the treated cats were monitored for approximately three years to better ensure the safety of the new treatment.

Once everything was clear, all nine of the study cats were eligible for adoption. Dr. Swanson took three of the lab cats home herself.

Swanson said the inspiration for this proof-of-concept study “was actually designed to address the problem of cat and dog overpopulation and the euthanasia of many of these animals in shelters.”

“The best way to avoid euthanasia,” he said told CNN“isn’t to have all those animals that don’t have a home.”

The study’s lead author, Dr. Vansandt, emphasized the positive impact the treatment could also have on rare or declining animal species.

Scientists estimate that feral cats kill between 1.3 and 4.0 billion birds and between 6.3 and 22.3 billion mammals annually in the US alone.

“I’m both a domestic cat advocate and a wildlife advocate,” Vansandt said. “Our technology has the potential to significantly improve the well-being of both.”

The Cincinnati Zoo CREW team collaborated on this project with researchers from Massachusetts General Hospital (MGH) and the Horae Gene Therapy Center, funded by the Joanie Bernard Foundation and the Michelson Found Animals Foundation

“A nonsurgical sterilizer for community and companion animals has been long overdue and will transform animal welfare,” said Gary K. Michelson, founder and co-chair of the Michelson Found Animals Foundation.