Ovariectomy an Option for Performance Mares and Molly Mules

Lacey is beautiful, full of personality, and very athletic--for a mule, that is. Her owners plan on showing their cherished mule when she is ready, but they face an obstacle that all owners of female mules or mares go through--heat cycles.

A female mule, or "molly," in estrus (otherwise known as heat) can make working, showing, or competing more difficult. Mules can compete in many of the same sports as horses, such as cutting, roping, or dressage. But both mares and mules experience frequent heat cycles through the spring and summer, which is also the season for competitive equine sports.

That is why Lacey's owners, Suzy and Eddie Epler of St. Maries, Idaho, decided to have her undergo a laparoscopic ovariectomy, a technically advanced and minimally invasive surgery to remove her ovaries.

"You can't breed a mule and we wanted to get rid of the heat cycles," Suzy Epler said. "She is our pride and joy and we want to keep her for a lifetime."

The Eplers heard about the procedure from their local veterinarian, Doug Walker, DVM, and that it is offered at the Washington State University College of Veterinary Medicine.

"Male mules and horses are often castrated to improve their behavior as performance animals and as pets in general," said Claude Ragle, DVM, Dipl. ACVS, Dipl. ABVP, a WSU associate professor and board certified equine surgeon. "In females, an ovariectomy operation can accomplish the same goal, but it is an option often overlooked."

"Young mollies are the ideal candidate for an ovariectomy because they are sterile and can't reproduce," Ragle said. "In the past, there wasn't a good technique to remove ovaries in female mules and horses. With laparoscopy, now there is a safe method."

Laparoscopy has emerged in veterinary medicine over the past decade as a type of minimally invasive surgery that allows for a faster recovery, less scarring, and less pain.

Ragle's interest in laparoscopy was initially spawned in the late 1980s when he was looking for a better way to perform ovariectomies in horses and mules. Since then, he has performed the procedure on hundreds of mares and mules, and has been called on to teach the technique all over the United States and abroad.

Being minimally invasive, the procedure can be done on a standing horse with local anesthetic blocks, rather than completely sedating a horse with general anesthesia. And because the incisions made are so small, many horses are able to return to athletic usefulness much faster than if traditional surgery had been performed.

In addition, the WSU Veterinary Teaching Hospital now utilizes an electrosurgical instrument, called a LigaSure, which seals blood vessels during laparoscopic surgery. This instrument allows ovariectomies to be performed faster and better.

"The LigaSure transects the ovary free without loss of blood or the use of staples or sutures," Ragle said. "This procedure is fairly new to the horse and mule world, so not that many people know about laparoscopic ovariectomy as an option and its potential benefits. Not only does it suppress the clinical signs of estrus behavior, making mollies or mares generally easier to train, it also reduces the chance of unwanted horses from indiscriminate over-breeding or those with genetic disorders. It is also an over-looked way for breeders to conserve valuable genetics by selling spayed, as opposed to fertile, mares. In addition, the equine ovary is not crucial to bone metabolism like in humans, so there is no need to worry about estrogen replacement because their bones are not affected," he said.

The standing procedure currently costs about $1,500 in average cases, which is very cost-effective compared to the expense and efforts involved with long-term hormone therapy to suppress estrus in the equine.

Horses and mules that undergo the procedure are held off feed or are put on a low-bulk diet a few days before the surgery. The surgery itself lasts about one hour, and the horse or mule is allowed to go home within a day or two after the procedure. The incisions take approximately two weeks to heal, and the animal typically can go back to work within three to four weeks.

"Lacey had the surgery before her first heat, and she recovered really well," Suzy Epler said. "It was actually really easy on her."

"For owners considering an ovariectomy, we like to see the animal when it is young, as soon as it is trained enough to stand in a stock for surgery," Ragle said. "There are a lot of mule owners that think females are nicer and less pushy than males, but don’t like them coming into heat. An ovariectomy may be an ideal option for them."

For more information about laparoscopy, ovariectomies, or to schedule an appointment, contact the WSU Veterinary Teaching Hospital at 509/335-0711.

Stay on top of the most recent Horse Health news with FREE weekly newsletters from TheHorse.com. Learn More