A new sterilization technique that leaves a stallion's testicles in place but nonfunctioning might provide a safe, simple, and reliable alternative to traditional castration methods, according to Iranian researchers.

In the "Section-Ligation-Release" (SLR) procedure, a horse's testicles are not extracted as in standard castration techniques. Instead, the two spermatic cords, which provide blood and nerve supply to the testicles, are clamped, severed, and sealed via a 2-inch incision on each side of the scrotum. Within two months, the intact testicles degenerate, and testosterone falls to levels similar to those of traditionally castrated geldings, according to the researchers, whose study is scheduled for publication in a forthcoming issue of Reproduction in Domestic Animals.

"It's just two small incisions followed by a few minutes of manipulation on the spermatic cords, and then you close up the wounds and it's done," said study author Siamak Saifzadeh, DVM, PhD, associate professor of veterinary surgery at Urmia University in Urmia, Iran. "It's so easy," he said--both for the horse and the horse's caretakers, as SLR requires less postoperative care than traditional castration.

The technique requires less postoperative care than traditional castration.
The new technique reduces the risk of postoperative bleeding and severe swelling at the incision sites or in the prepuce, which are common complications of standard castrations, Saifzadeh said. Risks of parasite and bacterial infections are also reduced in the SLR technique, he said.

The oxygen-deprived testicles gradually shrink and become a mass of benign fibrous tissue, whereas the surrounding tissues remain healthy and well-supplied with blood and nerves, Saifzadeh said. None of the five study stallions, aged 2 to 4 years, presented evidence of spermatic cord reattachment in the months following the procedure, according to the article.

The aesthetic benefits of SLR are not to be overlooked, Saifzadeh said, as the geldings have a more natural appearance with only slight scarring.

However, he noted that in order to distinguish SLR geldings from stallions, especially in the event of the sale of a horse, the castration must be noted in the horse's health records and identification documents.

Although the procedure is faster and less invasive than a standard castration, Saifzadeh said, SLR should nonetheless always be performed under general anesthesia for the safety of both the horse and the veterinarian.

About the Author

Christa Lesté-Lasserre, MA

Christa Lesté-Lasserre is a freelance writer based in France. A native of Dallas, Texas, Lesté-Lasserre grew up riding Quarter Horses, Appaloosas, and Shetland Ponies. She holds a master’s degree in English, specializing in creative writing, from the University of Mississippi in Oxford and earned a bachelor's in journalism and creative writing with a minor in sciences from Baylor University in Waco, Texas. She currently keeps her two Trakehners at home near Paris. Follow Lesté-Lasserre on Twitter @christalestelas.

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