Proper emasculator application, with the prominent external assembly nuts facing the testis and the correct perpendicular orientation to the spermatic cord, can help reduce the liklihood of complications arising.

Photo: Courtesy Dr. P.O. Eric Mueller

Routine equine surgical procedures are just that—routine. But that doesn’t mean complications don’t develop. Take castration, for example. It’s one of the most common elective surgical procedures performed in the field, but sometimes things go wrong. Veterinarians must be prepared well in advance to manage any postoperative problems, which for gelding can range from mild swelling to devastating intestinal prolapse.

To that end, P.O. Eric Mueller, DVM, PhD, Dipl. ACVS, professor and director of equine programs at the University of Georgia’s College of Veterinary Medicine, in Athens, reviewed how practitioners can prevent and manage castration complications in the field at the 2015 American Association of Equine Practitioners’ Convention, held Dec. 5-9 in Las Vegas.

In previous studies researchers reported a complication rate of about 10%, he said. Of those, the vast majority were considered mild, about 20% were considered moderate, and just 3% were considered severe. But severe can mean death in some cases, so knowing how to respond is crucial.

Of course, preventing complications is preferable to having to manage them, so he offered the following tips on castrating:

• First, be familiar with the pertinent reproductive anatomy and how to perform the procedure properly;
• Collect an extensive history on the patient, including any previous surgeries or congenital inguinal hernias (those the foal was born with in which intestines have burst through the inguinal canal, a natural opening in the body wall of the horse’s groin area, and into the scrotum or tissue around the sheath);
• Conduct a physical exam prior to surgery, including a thorough evaluation of the horse’s testes and inguinal areas. “The absence of one or both descended testes, a history of congenital inguinal hernia, or abnormal swelling or enlargement of the inguinal ring (there’s one at each end of the inguinal canal) should alert the practitioner to an increased risk of postoperative complications, at which time they should strongly consider referral to a surgery facility,” he said;
• Apply the emasculators (a castration tool that cuts through the spermatic cord, crushing the vessels providing blood to the testicles) properly, checking for hemorrhage before releasing the cord after emasculation.
• Ensure the patient is up-to-date on tetanus vaccination

Following surgery, Mueller recommended keeping the patient on stall rest for 24 hours to allow for close observation. Then, he said horses should have short periods of forced exercise (lunging or trotting, for example) for four to five days to help reduce edema (swelling). “Don’t just turn them out in the pasture,” he said, as it won’t necessarily ensure the horse will move enough to keep the swelling down.

Managing Complications

Moving forward, Mueller outlined several potential complications and how to address them.

Edema “Tell clients that horses will swell,” he said, “and that it will be most apparent three to five days after surgery.” Proper surgical technique can help minimize swelling, but you can’t always avoid it completely. Swelling should subside within two weeks of the procedure.

If substantial edema occurs, Mueller recommended:

• Exercising the horse;
• Administering non-steroidal anti-inflammatory drugs (NSAIDs, such as phenylbutazone) judiciously; and
• Cold-hosing the affected area a few times each day.

Mueller cautioned that if the swollen area becomes infected, a veterinarian might need to aseptically prepare and surgically open it to allow the area to drain.

Hemorrhage How to manage bleeding from the castration site depends on the severity, Mueller said. If there’s just a slow drip, he recommended keeping an eye on it but not necessarily intervening right away. Chances are, the blood will clot and the bleeding will stop.

One type of complication that might arise is arterial hemorrhage from the scrotum following improper application of the emasculator during castration.

Photo: Courtesy Dr. P.O. Eric Mueller

If there’s a slow stream of blood, apply a Carmalt clamp—a type of curved forcep—to the bleeding cord or blood vessel and leave it in place for 24 to 48 hours. During that time, he said, the horse should be kept on stall rest. He said that because vessels can still bleed following ligation (stitching or tying off), he does not apply sutures. He also noted that he doesn’t usually pack the scrotal incision on a regular basis to stop bleeding, but if he does, he recommended using a continuous gauze (crypt packing) instead of 4×4 gauze. He also noted that “if it’s going to bleed, it’s still going to bleed with packing.” However, the packing might exert enough pressure to slow or stop a minor bleed.

It’s rare to have significant hemorrhage associated with castration, Mueller said, but it does occur. In those cases, seek referral to a clinic for further treatment, if that’s possible. “Before transport, the practitioner should consult the personnel at the referral facility for recommendations on initiating intravenous fluid and broad-spectrum antimicrobial therapy, as well as additional considerations necessary to stabilize the horse for transport. In the meantime, practitioners should monitor the patient for signs of shock, and they can use abdominal ultrasound to try to identify the presence of intra-abdominal hemorrhage.

Prolapsed Tissue In some cases, tissue in the area of the incision—most commonly the inguinal or abdominal omentum (a fatty yellow tissue that surrounds some of the organs) or inguinal fat—can prolapse through the incision. In these cases, Mueller said the practitioner should examine the tissue closely via palpation and/or ultrasound to ensure the prolapsed tissue does not contain intestines. Then the veterinarian can remove the prolapsed tissue. If intestinal prolapse has occurred, the horse will require immediate general anesthesia to cleanse, replace, and retain the intestines, followed by immediate referral to a surgical facility. Luckily, he said, intestinal prolapse is quite rare, usually occurring within the first six to 12 hours of castration.

Penile Trauma “Penile trauma should not happen,” Mueller stressed. “Don’t mistake a penis for a testicle!” If such a mistake does occur, however, he said the horse should be transferred to a referral facility for further treatment.

Take-Home Message

“A thorough understanding of pertinent clinical anatomy, strict attention to asepsis and surgical technique, and proper postoperative exercise recommendations will minimize the incidence of complications associated with castration,” Mueller said. “However, when complications do arise, the practitioner should be able to quickly recognize and correctly and aggressively treat them to assure a rapid and successful outcome.”

About the Author

Erica Larson, News Editor

Erica Larson, News Editor, holds a degree in journalism with an external specialty in equine science from Michigan State University in East Lansing. A Massachusetts native, she grew up in the saddle and has dabbled in a variety of disciplines including foxhunting, saddle seat, and mounted games. Currently, Erica competes in three-day eventing with her OTTB, Dorado, and enjoys photography in her spare time.