Vet Explores Contraceptive Solutions to Prevent Horse Cull

March 5, 2014

AWHC Contributor

As the debate continues surrounding the government-appointed wild horse cull in Alberta, one veterinarian has been researching a more sustainable solution to manage the free-ranging horse population: a safe method of contraception.

Dr. Judith Samson-French is no stranger to utilizing contraception as a management tool — she’s used it for years to control the feral dog population on First Nations communities. Through the Dogs With No Names project, she’s found success by administering a contraceptive implant in female dogs that renders them infertile.

A similar method can be used for wild horses, she said.

Jay Kirkpatrick is the director of the Science and Conservation Centre at ZooMontana in Billings, Mont. The centre develops and distributes wildlife contraceptives — including porcine zona pellucida (PZP).

Kirkpatrick said the PZP injection has been used, with much success, in horses for 27 years.

“The beauty of this particular contraceptive is that it doesn’t disrupt cycling or the horses’ behaviours, which is very important for the herd,” said Kirkpatrick. “It’s the only known contraceptive that does not interfere with the endocrine system.”

The PZP injection can be administered using disposable darts and an injection rifle. The inoculation does not harm the horses, although Kirkpatrick said the dart can take them by surprise.

The contraceptive is about 95 per cent effective, he added.

In addition to horses, PZP has been used to manage fertility in zoo animals, urban deer and Catalina Island’s bison population.

“We’re hardly trailblazing by using this method,” said Samson-French, who operates out of Banded Peak Veterinary Hospital.

But research must be completed before a contraceptive method can be implemented. Samson-French said she’s been looking at numbers and waiting on information from trappers.

“You need to know the fertility rates, the gender distribution and to zone in on the population that’s causing the problem,” she said.

“We need to know where we’re starting before we know where to end. How many wild horses is too many?”

Until the trapping ends March 1, the veterinarian has been researching wild horse numbers and reproductive rates from similar types of herds in similar areas.

Alberta Environment and Sustainable Resource Development (ESRD) counted about 980 horses in the southern eastern slopes in 2013. The majority of these wild equines are found west of Sundre.

Despite culling in the area over the past number of years, the wild horse population near Sundre continues to thrive. Samson-French said this area would be ideal to implement a reproductive management project using PZP.

But before the contraceptive can be administered, the provincial government needs to be on board. Carrie Sancartier, a spokesperson for ESRD, said the ESRD’s Feral Horse Advisory Committee is expected to “look more closely at contraception and other options in future advisory committee meetings.”

Wild horse capture permits began being distributed by the province mid-January. Once captured, the horses become property of the licence holder, who may keep or sell the horses.

Samson-French said the project would be privately funded. The contraceptive costs $24 USD per dose, in addition to the fee of $2 for a dart.

A training session is required before PZP can be distributed.