An American research group has developed a single-dose contraceptive injection for domestic cats.
Stray cats put urban biodiversity at risk because they exercise their hunting instinct by attacking birds. Its reproduction rate is usually high, so populations need to be controlled.
American researchers have created a single-dose injection, which can be an effective, quick and safe control solution compared to more aggressive methods such as surgical interventions and even euthanasia.
A gene therapy that blocks ovulation makes this method of population control non-invasive. The results are published in Nature Communications.
Many stray cats in poor condition
It is estimated that 80% of a total of 600 million cats in the world are stray and most of them have health and well-being problems. In addition, they exert pressure on other populations, such as urban birds, according to the study authors.
“Feral cat overpopulation can also have negative effects on wild birds and other wildlife.“, explains David Pépin, from Harvard Medical School (Boston, USA) and co-author of the study.
To control the population of stray felines, these animals are usually arrested, taken to shelters and, in cases where surgical sterilization is not possible, mass euthanasia is performed, even of healthy specimens.
Faced with this situation, Pépin considers prioritizing the development of a sterilization mechanism that does not require aggressive techniques such as surgery and, at the same time, allows “address the significant ethical, economic and environmental issues associated with stray companion animals“, in his own words.
contraceptive vaccine test
The Cincinnati Zoo and Botanical Garden participated in the test conducted on nine sexually mature females. Six of them received the contraceptive injection and the other three did not, during two attempts of four months each.
None of the six cats that received the injection became pregnant and, on the contrary, the three females in the control group had kittens.
The application of the injections managed to suppress the induced ovulation and reduce the levels of progesterone, a fundamental hormone for the gestation process, as it prepares the uterus for the implantation of the fertilized egg.
Contraceptive therapy is based on the administration of an anti-Müllerian hormone (AMH) transgene, a glycoprotein that inhibits the development of the Müllerian ducts, responsible for the formation of the cervix, uterus and fallopian tubes. Likewise, this marker has been shown to have a suppressive effect on the maturation of ovarian follicles in mice.
“The AMH gene is highly present in vertebrates, where it always plays a role in sexual differentiation and reproduction.“, details the Harvard Medical School researcher. Therefore, “this method is very likely to work in other species of mammals and we are currently testing its use in dogs“, To add.
At the moment no side effects of the contraceptive injection
It should be noted that after the test, the cats were followed for two years and the scientists did not record any adverse reactions.
While further testing is still needed to confirm its safety and effectiveness, the method promises to be a quick and easy-to-use option for inducing permanent contraception in domestic and stray cats.
“We can adapt this technology to control invasive species“, emphasizes Pepino. However, the biologist qualifies that “for each species we must match the AMH sequence with its genome“.
Pépin, D. et al. “Durable contraception in domestic cats using administration of a viral vector of a feline anti-Müllerian hormone transgene” Nature Communications (2023)