A Flagstaff, Arizona scientist may have discovered a nonsurgical way to sterilize dogs — an advance that would revolutionize animal-shelter medicine and address many states’ canine-overpopulation problem in the process.
Dr. Loretta Mayer was looking for a way to artificially induce menopause in mice so they could be used to study human diseases when she and another scientist developed a drug that they realized also could be used to sterilize female dogs, removing the need for painful and expensive surgery.
And while previous nonsurgical sterilization products have had mixed success, Dr. Nancy Bradley, director of medical services with the Arizona Humane Society, said that if one sterilization drug proved to be safe and successful, she would use it in a heartbeat.
Mayer’s path to contributing to a scientific breakthrough was not a direct one, however.
First, Mayer worked with Dr. Patricia Hoyer, an ovarian toxicologist, and together they developed a drug they dubbed “mouseopause” that induced menopause in female lab mice by eliminating eggs in the ovaries without surgery.
By 2007, Mayer began testing ContraPest, SenesTech’s version of “mouseopause,” on rat populations that devastate rice fields in Indonesia. The drug provides an alternative to poison, which many Southeast Asian farmers use to deal with rats.
“I would really like to see us do things that improve our environment and are compassionate to other beings,” Mayer said. “My passion, without question, is to stop killing animals, however we might do that.”
Mayer, a dog lover, then developed Chemspay, a contraceptive drug for female dogs that can be administered orally or by injection. Mayer and SenesTech tested the contraceptive from 2004 to 2008 on dogs . The trials proved that Chemspay reduced the number of eggs in the tested dogs significantly, making them sterile.
“This technology, if successful, will really have a huge impact on unwanted dog populations,” Mayer said. “The biggest impact will be where dogs are reservoirs for human diseases, like in India.”
Although Chemspay is about six to nine years away from being approved by the FDA, Mayer hopes to begin FDA-approved trials in about three years at the Second Chance Center for Animals in Flagstaff, Arizona.
