Equine and Camelid Castration

Castration Planning

As with any surgery, preplanning is crucial.

Work through this narrated powerpoint (3.25 minutes):

After viewing the introduction above, watch the video below (through 1:30 at least) to get an overall picture of recumbent equine castration. As you watch, think about:

  • how old (big) is the colt?
    • (I like the boys to be older/bigger vs younger/smaller. The young ones have teeny floating testicles that are hard to hold still for removal. Some people worry about castrating adult stallions. I think old stallions are easier.)
    • Some colts are so obnoxious  (stud like, aggressive and/or attempting to breed Momma) that we have to castrate them at an earlier age
  • what season is it?
    • fly season is more challenging for wound management
  • where are they performing the castration?
    • I like open grassy areas
  • how does the colt become recumbent and stand up again (how much help does he need)?
    • most horses will pull back if you pull forward; this can be very useful to help them lie down gently
  • how do they keep the hindlimb out of the way?
    • good time to review your knot tricks
  • where does the surgeon stand to perform the castration?
    • avoid those feet!
  • what level of sterility is being used? caps/gowns/masks and gloves (good idea) or something else?
    • if we leave this open and have good drainage, is this level of sterility okay?

This gives a nice big picture overview of the process

How does the video compare with what was suggested in the powerpoint above?


Level A. Now work through this quiz to review a few more factors:

Plan for complications

It is also good to plan for complications and be prepared. The most common complication is postoperative swelling.  Other complications include

To prevent facial nerve paralysis, it is important to remove the halter to for recumbent anesthesia. This avoids pressure on the nerve. To prevent radial nerve paralysis associated with recumbent anesthesia, the down forelimb should be drawn forward so that it is in front of the body. This decreases the direct pressure on the nerve. Assign someone with the roles of making sure these things happen. [If nerve paralysis does happen, time and steroids can help. Facial nerve paralysis has minimal complications. Radial nerve paralysis freaks out the horse and the limb needs to be splinted so they can use it properly. [Freaked out horses have less brain function than normal.]

Hemorrhage is minimized by using the appropriate means of hemostasis for the animal. For younger colts, about any technique will work as long as it performed appropriately. For larger stallions, an emasculator may not provide sufficient clotting if it is also trying to crush the other structures in the spermatic cord. These do better if the tunic is opened so the artery can be crushed separately and/or ligated. Ligation can be combined with emasculation for additional security.  Add ligatures and different size emasculators to your truck.

Evisceration is difficult to prevent but those animals at risk should be identified. In particular, animals with inguinal hernias as foals or requiring cryptorchid surgery are at greater risk due to the larger size of the inguinal ring. Surgery at an equine hospital may be indicated. If not, bring supplies to manage escaping guts (sterile towels, vetwrap, suture and an assistant)

Infection is managed through preoperative antibiotics and good drainage. Large incisions and postoperative exercise will minimize the risk. Warn your owner in advance. This is not a good time to put the colt in a stall for a week.

As horses are very sensitive to tetanus, all surgery patients should be well vaccinated prior to surgery.

Key Takeaways

Why – Stallions can be dangerous and are difficult to house safely with other horses.

Who –Healthy, vaccinated, trained colts that are at least 6 months old and have two testicles . Castration is an elective procedure.

When- Spring is ideal since fewer bugs, but it depends on where you are practicing.

Where –  An open grassy field is the best. Avoid stalls, wooded areas and slopes.

How – I prefer recumbent open castration. Castration can also be performed standing.

What else – Preoperative and postoperative analgesics and tetanus are necessary. Preoperative antibiotics recommended. Owners need to be prepared for the aftercare.



Two Regimes of Perioperative Antimicrobial Prophylaxis for Equine Castration. Journal of Equine Veterinary Science 57 (2017) 86–94

BEVA primary care clinical guidelines: Analgesia; Equine Veterinary Journal, January 2020, Vol.52(1), pp.13-27

Key guidelines produced by the panel included recommendations that horses undergoing routine castration should receive intratesticular local anaesthesia irrespective of methods adopted and that horses should receive NSAIDs prior to surgery (overall certainty levels high). Butorphanol and buprenorphine should not be considered appropriate as sole analgesic for such procedures
(high certainty). The panel recommend the continuation of analgesia for 3 days following castration (moderate certainty) and conclude that phenylbutazone provided superior analgesia to meloxicam and firocoxib for hoof pain/laminitis (moderate certainty), but that enhanced efficacy has not been demonstrated for joint pain. In horses with colic, flunixin and firocoxib are considered to provide more effective analgesia than meloxicam or phenylbutazone (moderate certainty)



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Large Animal Surgery - Supplemental Notes Copyright © by Erin Malone, DVM, PhD is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License, except where otherwise noted.