The Equitwister: A Simplified Way to Castrate Working Equids

The Equitwister—made of stainless steel rod, PVC pipe, and a crank—costs less than $5 to make.

Photo: Tracy A. Turner, DVM, MS, Dipl. ACVS

One of the most common (and some might say important) surgical procedures veterinarians perform on working equids is castration. While it’s generally considered a quick, easy, and inexpensive procedure in developed countries, where horse owners have the resources to ensure all goes as well as possible, castration can be cost-prohibitive and/or lead to complications in rural communities.

So Tracy Turner, DVM, MS, Dipl. ACVS, ACVSMR, of Turner Wilson Equine Consulting, in Elk River, Minnesota, developed a simple, cheap castration tool for use in equitarian—or volunteer equine veterinary--work: the Equitwister. He described its use during a presentation at the 2015 American Association of Equine Practitioners Convention, held Dec. 5-9 in Las Vegas.

Castration is important in developing countries, said Turner, for improved equine behavior and handler safety; to prevent pregnancies in working mares; and to promote more selective breeding for better animals.

So why the need for a new castration tool?

“In equitarian work, castration is typically done on a single day in a community during a yearly visit,” Turner explained. “Due to the lack of ability to follow up on these patients, it is imperative that reliable techniques with few complications be used. In addition, these techniques are often simultaneously taught to local veterinarians or veterinary students. Ideally, the techniques should be simple, easily repeatable, and use equipment that is affordable.”

Common castration complications that know no socioeconomic bounds include hemorrhage, swelling, infection, and evisceration (protrusion of the intestines through the surgical site). In addition to the impracticality of veterinary follow-up, these occur more frequently in developing countries because of the logistical challenges of keeping wounds clean.

In the past, equitarians have relied on the Henderson castration tool, which clamps around the spermatic cord, attaches to a power drill, and twists off the testicle. This twisting technique helps prevent hemorrhage.

But because sustainability—the locals’ ability to continue veterinary work after equitarians leave—is an important part of equitarian work, the Henderson tool is impractical if for no other reason than cost, said Turner.

“In the case of the Henderson technique, the clamp is expensive, the power drill is expensive, and castrations may be performed in areas without (electricity) access to recharge batteries, making the tool unusable,” he explained. Each tool costs $200-400, which in a country whose annual income ranges from $1,600-6,800, is impractical.

Enter the Equitwister. Made of stainless steel rod, PVC pipe, and a crank, it uses a similar approach to the Henderson tool in how it twists the spermatic cord, but though it’s manual, it requires little effort. It also costs less than $5 to make.

“The Equitwister is easier to use, much less expensive, and as effective as any castration technique today,” said Turner, who has been using prototypes since 2014 and continues to make improvements.

He said the procedure results in hardly any hemorrhage and, after the horse undergoes general anesthesia, can be performed in under a minute. In fact, Turner said he’s performed more than 200 Equitwister castrations and encountered only one hemorrhage and one evisceration in field conditions.

In Turner’s experience, “the slow twist of the Equitwister is superior to the power twist of the Henderson tool because the spermatic cord is less likely to double on itself and the slower speed provides a tighter twist.”

In summary, he said the Equitwister is ideal for equitarian work. To date, he’s trained more than 50 veterinary students to use it. The Equitarian Initiative sells these tools to raise money for their projects at

About the Author

Alexandra Beckstett, The Horse Managing Editor

Alexandra Beckstett, Managing Editor of The Horse and a native of Houston, Texas, is a lifelong horse owner who has shown successfully on the national hunter/jumper circuit and dabbled in hunter breeding. After graduating from Duke University, she joined Blood-Horse Publications as Assistant Editor of its book division, Eclipse Press, before joining The Horse.

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