Researchers have developed a gene therapy injection for permanent contraception in female cats that does not require invasive surgery.
The global cat population is estimated to be around 600 million, with about 80% being feral cats. These hunters cause significant harm to wildlife. In the United States alone, cats kill between 1.3 to 4 billion birds and between 6.3 to 22.3 billion mammals each year. Currently, the primary method for spaying cats is surgery, a costly and risky procedure.
Spaying female cats currently involves invasive surgery, which is expensive and carries a risk of infection. (Photo: Shutterstock).
The New Spaying Method, described in Nature Communications, involves gene therapy that creates long-lasting contraceptive effects for female cats. However, testing of this method is still in the early stages, small-scale, and includes only 9 cats. By the end of this year, researchers plan to expand the testing, according to David Pépin, a molecular biologist at Harvard Medical School and co-author of the study, speaking to Inverse.
Today, spaying a cat means surgically removing their reproductive organs. This invasive procedure increases the risk of infection and hemorrhage, and cats typically take 7 to 10 days to recover.
“Surgery, especially in feral cats, is very stressful and costly since it requires capturing the cats, transporting them to a surgical facility, performing the surgery, and providing post-operative care,” said Aime Johnson, a veterinarian at Auburn University. Because the surgery must be performed by specialists, funding for spaying feral cats is not always available. With the new spaying method, a single injection is all that is needed, and the cats can be released immediately.
In the trial, female cats were injected in their thigh. The injection consisted of the “shell” of a virus that had been rendered non-pathogenic, containing genetic material (DNA) inside. This DNA stimulates the cat’s muscles to produce a type of protein known as Anti-Mullerian Hormone (AMH), until AMH levels reach 100 to 1,000 times the normal level, preventing the ovaries from maturing and releasing eggs.
To test the efficacy of the injection, researchers placed the injected female cats into two breeding cycles, each lasting 4 months. They confined 9 cats with a previously fertile male and recorded video of their mating interactions.
The results showed that 3 unmedicated cats became pregnant and gave birth to healthy kittens, while 6 medicated cats did not become pregnant.
However, these findings should be regarded as “extremely preliminary,” said Daniela Chavez, a feline reproductive biologist at Towson University who was not involved in the study, to Atlantic. Further research is needed on larger groups of cats to confirm whether the treatment is safe and how long its effects last.
