Study discovers contraception alternative for female cats
"This breakthrough discovery is a major milestone in our quest to provide pet owners with an alternative to surgical spay and neuter" – Gary K. Michelson.
Scientists in the USA have demonstrated that a single dose of anti-Müllerian hormone (AMH) gene therapy can produce long-term contraception in female domestic cats.
It is hoped the breakthrough in feline sterilisation will eventually aid efforts to reduce free-roaming cat populations, which can be too large for spaying to be effective. In the USA, for example, there are an estimated 600 million free-roaming domestic cats.
Researchers from the Cincinnati Zoo & Botanical Garden’s Center for Conservation and Research of Endangered Wildlife, the Massachusetts General Hospital, and Horae Gene Therapy Center treated six female cats with a single injection of an adreno-associated viral gene therapy vector with a slightly altered version of the AMH gene.
AMH is a naturally occurring hormone produced by mammals. In cats, it is secreted by ovarian follicles.
After treatment, two four-month long breeding trials were performed, the first after one year and the second after two years. Three untreated cats, used as controls, produced kittens, but none of the cats which had been treated with AMH became pregnant.
During the study, regular health checks found no adverse side effects from the treatment.
Gary K. Michelson, founder and co-chair of the Michelson Found Animals Foundation, which helped fund the study, said: “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.”
As well as helping resolve welfare issues by reducing the number of free-roaming cats, it’s also hoped that controlling numbers will benefit wildlife.
Jenny Gainer, curator of birds and African animals at Cincinnati Zoo & Botanical Garden, said: “Cat predation is a major source of mortality in wild birds. Outdoor cats also contribute indirectly through fear, resource competition, and disease transmission. Controlling and reducing the population of free-roaming cats will make a major difference for declining songbird populations.”
However, it may be a while before the gene therapy is used regularly for feline sterilisation, as there is not currently the right infrastructure in place to mass produce the treatment.
The study has been published in Nature Communications.
Veterinary practices are being urged to help owners safely dispose of any unused and expired pet medicines - not just antibiotics - during November's Animal Medicines Amnesty. 
