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Castration refers to the surgical removal of the testes. The testes are comprised of the right and left testicles and epididymides. Castration is also referred to as orchiectomy, emasculation, gelding or cutting.


Pertinent Anatomy

Anatomy of a Testicle


Testicle & Epididymis: Structures that produce sperm cells and testosterone (sex hormones). These tissues, covered by a layer of tunica albuginea, are targeted (removed) during the castration procedure.

Vaginal Tunic: Tissue which houses the testicle, epididymus and spermatic cord on each side of the horse. The vaginal tunic is composed of two layers:

  • The visceral tunic (which adheres to the tunica albuginea) and

  • The parietal tunic (which is continuous with the parietal peritoneal lining of the abdomen).

Abdominal fluid fills the (vaginal) space between the visceral and parietal tunics.

Scrotum: The skin surrounding the testes. Each testicle resides within its own scrotal sac. The two scrotal sacs are separated along the midline by the median raphe.

Spermatic Cord: A plexus of structures which is comprised of the vaginal tunic, testicular artery, vein and nerve, ductus deferens, lymphatic vessels, cremaster muscle and genitofemoral nerve.


Preoperative Considerations

In the vast majority of cases, castration is an elective procedure. We therefore want to ensure that the horse is in good health and free of concurrent illness prior to planning the operation. Maximizing the surgical candidacy of the patient will minimize the risk for potential complication(s).A thorough physical examination (sometimes including bloodwork) is an imperative part of the preoperative process. Any illness discovered during preoperative assessment is successfully treated prior to scheduling orchiectomy.

Castration is generally scheduled in the morning to facilitate close monitoring throughout the day of surgery.

BOTH testicles are manually palpated to confirm that each has successfully descended into the scrotum. If either or both testicles are not detected, then cryptorchid castration may be considered.

Tetanus is a very real concern with regard to any violation of the horse's integumentary system (skin). We therefore confirm that a Tetanus Toxoid has been administered within 6 months of castration. If this can't be confirmed, then one is administered preoperatively.

Single doses of Procaine Penicillin (antibiotic) and Pheylbutazone (antiinflammatory) are administered immediately preceding the procedure.

At The ATLANTA EQUINE Clinic, we typically perform routine castration in the standing, sedated animal.



The scrotal region is surgically prepped. A minimum of 6 minutes of contact time between a bacteriocidal soap and skin surface is allowed to ensure sterility of the surgical site.

The testicular and genitofemoral nerves are blocked using a suitable anesthetic agent (usually Carbocaine®). The skin along the median raphe is also anesthetized.

An incision is made parallel and adjacent to the median raphe into one of the scrotal sacs. The incision is usually about 15-20cm in length.

The testicle is identified within the parietal tunic, which is manually separated ("stripped") from surrounding tissues.

If possible, the testicle (within the parietal tunic) is retracted out of the incision. Ample exposure of the testicular structures within the parietal tunic will allow for closed castration.

In most cases, the parietal tunic must be partially incised to allow for ample retraction of the testicular structures away from the scrotum. In these cases, modified-closed castration is performed. Everted parietal tunic is removed in conjunction with testicular tissues.

Once the testicular structures have been amply retracted, emasculators are applied around the vaginal tunic (to include all of its contents). Proper application of this device results in the "crushing" of tissue (that will remain in the horse) to ensure adequate hemostasis.

As the emasculators are engaged, the distal aspect of the spermatic cord is simultaneously cut below the level of crushed tissue, thereby allowing for complete removal of the testicular structures.

The emasculators are left in place for a minimum of 3-6 minutes (per side) to ensure adequate clotting of the testicular vasculature (hemostasis). We prefer as little post-operative bleeding as possible.

Immediately following removal, the tissues are carefully inspected to confirm that all target structures have been successfully excised. The entire testicle and epididymis must be resected; visible evidence of a portion of the vas deferens (which resides above the testicular tissues in the horse) confirms successful orchiectomy.

Click HERE to review the testicle inspection process.

The other testicle (with its associated structures) is removed in similar fashion.

In some cases, photographic images of the testicles are acquired to provide the owner with verification that the horse has been successfully (and completely) castrated.

Immediately following resection of both testicles, each incision is carefully inspected for evidence of hemorrhage (bleeding). Further measures to address any hemorrhage are taken at this time.

Following inspection of each incision, the median raphe and excess scrotal fascia are resected to allow for improved postoperative drainage of the incision(s). This results in further hemorrhage, but previous inspection of the individual incisions (see above) verifies that ancillary bleeding is superficial (local) in nature and not related to emasculation of testicular tissue(s).

Deeper fascia is manually stretched to enhance post-operative drainage of the scrotal defect. Many horses can be disagreeable during this exercise, as they are beginning to come out of sedation by this point.


Postoperative Recommendations

Depending on the condition of the colt and environment at the time of the procedure, post-operative medications may be suggested by the veterinarian.

KEEP YOUR HORSE MOVING AFTER SURGERY. Incisional drainage is an essential part of successful post-operative care. The incisions are deliberately lengthened and the septum (separation) between the scrotal sacs (called the median raphe) is removed to enhance post-operative drainage. However, the predisposition for swelling (edema) and infection are considerably increased if the horse is not exercised following surgery. Frequent movement keeps the incision sites open and allows for proper drainage. Therefore, force your horse to exercise (at a trot) several times a day for at least 2 postoperative weeks.

Begin exercise as soon as the horse recovers from sedation.

Cold-water hose the incision sites. Hosing the castration site at least once daily can help to reduce/ prevent edema. Hosing also stimulates many horses to kick, which further opens the incisions and enhances drainage.

Monitor the castration site CLOSELY for increased hemorrhage (bleeding), swelling, heat, pain, or any other abnormality(ies) for 10-14 days after surgery. Also, monitor your horse’s attitude, activity, appetite, and temperature DAILY.

Castration is generally scheduled in the morning to facilitate close monitoring throughout the day of surgery. If you turn your horse out, please make sure he will be visibly assessed at least twice daily.

Further medical therapy (such antibiotics or antiinflammatories) may be warranted depending on the level of concern, the appearance of the castration site and/ or the comfort and general condition of your horse.

Please note that your horse may successfully breed a mare for up to 10-14 days after castration. Change in demeanor and attitude as a result of castration generally takes 30-90 days, depending on the age of your horse.


If you have any questions regarding Routine Castration in the Horse please call our office at (678) 867-2577. We look forward to serving you!
THE ATLANTA EQUINE CLINIC: 1665 Ward Road, Hoschton, Georgia 30548 - ph. 678-867-2577

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