It's early yet, but a single injection into an animal's muscle tissue could one day replace the traditional, invasive, and expensive, spay-neuter method used on both feral animal populations and home pets.
In the October 5 issue of Current Biology, researchers from the California Institute of Technology report on the results of a new proof-of-concept injection that neutralizes male and female reproductive hormones, rendering an animal unable to create offspring.
Senior study author Bruce Hay took aim at gonadotropin-releasing hormone (GnRH), which is made in the brain and is key to the secretion of reproductive hormones that, in turn, stimulate sperm and egg production. Stop GnRH from doing its thing, and you get an infertile animal, the thinking went.
Hay and his team were able to do exactly that, neutralizing GnRH with one shot delivered into the animal's muscle. The scientists say the shot should be good for the lifespan of the animal.
The news comes with two excitement-tempering caveats, though. First, as in so much research, the injection has so far only been used on mice. And, second, the team noticed a two-month lag time between the injection and the onset of infertility.
Nonetheless, it's a start.
"Spaying and neutering wild animals is not a trivial process," said Hay in a press release. "It takes money and time to anesthetize them, do the surgery, and let them recover. This is a much more benign way of managing populations."
For now, work will continue on ways to drastically reduce the two-month lag time, and Hay's team is working on a pilot study with female cats, to be run in collaboration with staff from the Cincinnati Zoo.