Castration Summary Points

Key Takeaways

• Castration is an elective procedure. Make sure your patient is healthy, able to be handled and has 2 testicles
  • Early castration leads to delayed growth plate closure and taller, finer boned and straighter-limbed animals
  • Early castration may result in narrowed urethras
• Give analgesics preoperatively to prevent windup phenomenon. Local blocks help.
  • continue analgesics postoperatively
• Most recumbent anesthesia procedures use xylazine combined with ketamine. Adding butorphanol, diazepam or midazolam, or guafenesin can increase the effective duration and smooth recovery. Typically butorphanol and/or a benzodiazpene is added. Drips (GG combos) are less common but super useful.
  • Detomidine gel is absorbed through mucous membranes and can provide some sedation (takes about 30 min to work)
  • Diazepam doesn’t play well with others; can be mixed with ketamine but not xylazine
• Tetanus toxoid is required. If the horse has been vaccinated within the past 6 months, that is usually considered adequate.
  • Tetanus antitoxin has side effects.
• Preop penicillin (or ceftiofur) may decrease complication rates. Giving after the procedure is not as effective.
• Surgery and recovery is best done in an open grassy field.
  • Field recoveries are generally low risk even with wild things but finishing with xylazine or romifidine (1/4 dose) can help smooth things
  • You can keep a horse down by controlling the head and neck (sit on the neck, hold the nose up)
  • Remove the halter to avoid pressure on the facial nerve
  • Work from the backside (back bone) of the horse whenever possible – not in the kick zone
• Closed castration is preferred in young animals; open castration in horses with large arteries
  • The more I do, the less I like closed castrations
• Don’t remove any testicles unless you are sure you can see both
• Plan for complications and ensure you have needed supplies
  • Especially suture and more drugs
• If hemorrhage or evisceration develop, re-anesthetize the horse.
• Most common complication is postoperative swelling due to early closure of the wound
  • Exercise is important for minimizing swelling postop
  • Make big holes and stretch the skin to make the incision as big as possible
  • Leave holes open!
  • If the incisions close, they can be reopened using your fingers. Twitch the horse first!
• Inguinal hernias in foals usually resolve on their own. Surgery or medical care is not needed.
• Cryptorchid stallions are not ideal breeding candidates.
• Proud cut doesn’t exist despite continued beliefs from horse owners and horse vets
  • So just remove the epididymis and don’t blame it
• You have less control over standing castrations