A cautionary tale
But castration does NOT always go so well. Yes, most horses do fine. But there can be expensive complications, and a few actually die. My friend recently gelded her horse, and despite her best efforts her horse has experienced infection and other complications that will cost her into the thousands. I'm not into scaring people, but I would like to encourage owners to be vigilant and attentive to their recently gelded horse. Follow the post-op instructions, and call the vet if excess bleeding, fever, or swelling occurs.
When to geld
In very young horses, the testicles up in the abdomen or inguinal canal. Testicles must be "dropped" into the scrotum in order to perform field surgery. Usually this happens by the time the horse is a yearling. Gelding early reduces the risk fo complications, because the genitalia and blood vessels are not as big/developed in the young horse as in a full-grown adult. As a horse gets older, the surgery will become more involved/risky. Horses gelded earlier will grow taller, because testosterone tends to cause the horse's growth plates to close early.
You'll want to geld in spring or fall; it should not be too cold for the surgeon to operate in the field, but fly season should be avoided. A sunny, dry day is best. Avoid castrating when the horse will be exposed to wet/muddy conditions.
Spend some time getting your horse used to being handled in the nether regions. Depending on the post op care recommended by your vet, you may need access to the surgical site to cold hose or clean it. Find a grassy, clean spot with bright sun for the surgery. My vet did the surgery on the side of an incline, which did turn out to be helpful in dropping Riley safely. Make sure your horse is current with his vaccinations (especially tetanus) and worming.
Standing surgery: Frankly I don't know much about this. I assume a local anesthetic is used and some brave vet does the snipping while crouched underneath the animal. This can only be performed on relatively tall horses (no ponies, no minis). The advantage is that the risks of the anesthesia are avoided, and the wound is left open to drain. There are generally no sutures which could invite infection. It is riskier for the vet, and in the event of catastrophic problems (bleeding) the horse will need to be anesthetised.
Recumbant (dropped) under anesthesia: The horse is sedated/anesthetised and "dropped." The procedure is quick, perhaps 10-15 minutes, and the horse is allowed to wake up and stand. There are sometimes sutures. The advantages are that it is safer for the vet, and the vet has easy access to the genitals; the disadvantages are slightly higher risk of infection (sutures) and complications from anesthesia.
Clinic surgery: This is the only option for horses that have not dropped their testicles. It is relatively safe, with some risks from going under a general anesthesia. The surgery occurs in a sterile setting, and the wound is closed following the procedures, so complications from infection/bleeding are rare. The main disadvantage is cost.
The horse is "dropped" -- anesthetized. While lying on its side, the vet makes two incisions, one over each testicle. The tissue surrounding each testicle is removed, leaving the testicle, epididymis, and spermatic cord. Emasculators -- a tool used in castration -- are used to crush the blood supply in the spermatic cord. The cord is then severed and the testicular and associated tissues are removed. The emasculators are left in place for up to two minutes. Usually, the wound is left open to drain.
Generally antibiotics and painkillers are prescribed. Bleeding is normal, but drops should come at a rate that you can count them individually. If it becomes a stream, contact the vet. Bleeding may continue for days after the surgery. You can apply vaseline to hind legs where blood may come in contact with the skin (prevents scalding). Let the horse rest the first day, and keep him in a clean environment After the first day, exercise is important. Pasture him with a quiet buddy or by himself, but do make sure he moves, walking and trotting, for an hour a day. This keeps the wound open and draining. Some vets advise cold hosing, others will tell you not to bother the site. Watch the site for excessive swelling Unusual smells are a sign of infection -- call the vet immediately.
None of these scary complications is common. But forwarned is forearmed!
- Eventration occurs when part of the abdominal contents (most commonly loops of small intestine) comes out through the incision site or down into the scrotum. This usually occurs within the first few hours of surgery, but may occur days following the procedure. Call the vet immediately.
- Bleeding can be a serious complication. Again, call the vet at the first sign of unusual bleeding.
- Because the castration incision must be left open to drain serum, infection is another common complication. Castration sites need to heal from the inside out. If the outside skin heals first, serum and blood can accumulate in a pocket and the site will become infected.
- If too much spermatic cord was pulled out of the abdominal cavity during the surgery, the stump may retract into the abdomen. This can cause bleeding and infection that requires additional veterinary attention.
Castration in horses from The Horse Magazine
Gelding and aftercare by Cherry Hill, author of Horsekeeping
Castration surgical procedures from The UC Davis Book of Horses