Currently there are no contraceptives capable of producing permanent sterilization in companion animals. Spaying, the surgical removal of the ovaries and uterus, is the most widely used strategy to control unwanted reproduction in female cats. For the first time, researchers at Massachusetts General Hospital (MGH), a founding member of Mass General Brigham (MGB), and their collaborators have demonstrated that a single dose of anti-Müllerian hormone (AMH) gene therapy can induce long-term contraception in the domestic cat, potentially providing a safe and effective alternative to surgical spaying. The research is published in the latest issue of Nature Communications.
The researchers treated six female cats with the gene therapy at two different doses, and three cats served as controls. A male cat was brought into the female colony for two four-month-long mating trials. The researchers followed the female cats for more than two years, assessing the effect of the treatment on reproductive hormones, ovarian cycles, and fertility.
All the control cats produced kittens, but none of the cats treated with the gene therapy got pregnant. Suppressing ovarian follicle development and ovulation did not affect important hormones such as estrogen. There were no adverse effects observed in any of the treated female cats, demonstrating that at the doses tested, the gene therapy was safe and well tolerated.