Contraceptive implant targets feral dog population

Bragg Creek, Alberta — A pilot study using deslorelin contraceptive implants in 15 semi-feral female dogs is showing promise as a way to control feral dog populations.

The study was conducted on the Tsuu T'ina Nation reserve near Calgary and is providing hope to a Bragg Creek veterinarian that more unwanted births can be prevented.

"Many of these dogs freeze to death. They give birth in winter, with no water to nurse their puppies," says Dr. Judith Samson-French, owner of Banded Peaks Veterinary Hospital. "They are bred every heat cycle, and we're having females out here with 16 puppies per little. A lot of them live miserable lives."

At least 700 dogs roam free on the 109-acre reserve, and about 80 percent are unnamed and unwanted, Samson-French says. Cold winters present enough hardship for the dogs, which also fall victim to heavy parasite infestation, starvation, dehydration and cannibalism. Spay/neuter programs have been in place for several years on the reserve but have not been very effective. Plus, no one is tracking how long the dogs that are sterilized survive, since feral and semi-feral dogs only live an estimated two to three years in the far north.

"It's too difficult to catch the feral dogs," adds Samson-French. "In northern climates, feral dogs can not hunt. They do not know how to hunt. So feral dogs have to scavenge. They end up at the dump, and by January and February, they form packs. They don't live very long."

So Samson-French, with the help of the Animal Rescue Foundation (ARF) and an animal health technologist at the Calgary Zoo, sought a new plan for controlling the population of unwanted dogs on the reserve.

About nine months ago, Samson-French, Julie Felber of ARF and Lori Rogers of the Calgary Zoo implanted 15 semi-feral female dogs on the reserve with a contraceptive called deslorelin, introduced in 2004 by Peptech Animal Health of Australia. The contraceptive suppresses reproductive hormones in animals for 12 to 18 months and is used by several zoos. But the product is labeled for use in male dogs, and the women had to get special permission to conduct the pilot study. The project marks the first time the device ever has been used in female dogs.

Along with each implant, the dogs received rabies vaccinations, were dewormed and were microchipped. They will be implanted again in the fall, and a new batch of dogs were to get implants in mid-March. The implants cost $68 each, which Samson-French and ARF paid for. Samson-French said she hopes their program's success will result in wider use and lower cost for the contraceptive implant.

She will present a poster on her project at the Alliance for Contraception in Cats and Dogs non-surgical contraceptive symposium in Dallas this month and is working on starting another pilot study in Mexico.