Latest News


A colt castration is a routine procedure performed in first opinion equine practice. It can be done in one of two ways:

  • Standing (sedated)
  • Down (under GA)

As a practice we most commonly perform the castration with the colt standing. Reasons for doing it down would be:

  • Size of the animal (Shetland)
  • Size of the testicles (too small)
  • Temperament of the horse (too risky for the vet)
  • If it was a Donkey

There are two main ways to perform the castrate, either OPEN or CLOSED. This refers to whether or not we incise (cut) into the sack which goes around the testicle. In our practice we always perform the castration OPEN. This means your colt will be left with two incisions (holes) through which any blood etc can drain.

How to prepare your horse before the operation

  • We normally recommend that you starve your colt overnight and withhold water an hour before the operation.
  • The operation will always be carried out in the morning and you should make sure you have the rest of the day free for regular checks on your horse.
  • Make sure your horse is up to date with TETANUS vaccinations, if not we can start them the same day. The 2nd vaccination is given 4-6 weeks later.
  • Put a fresh straw bed down in the morning of the operation.

The vet will always talk through the castration procedure with you at the time of the operation but the list below covers the main points. The vet will:

  • Listen to the heart
  • Check there are two testicles present
  • Sedate the colt
  • Apply tail bandage
  • Administer antibiotics, painkillers and tetanus antitoxin
  • Clean the scrotum
  • Inject local anaesthetic into each testicle and cord
  • Clean the scrotum again
  • Using sterile gloves and instruments cut the skin and expose the testicle
  • The cord will be emasculated (special instrument to prevent bleeding and remove the testicle)
  • The same will be performed for both testicles


With any procedure there is an element of risk. Risks and complications associated with a standing colt castrate would include:

  • Bleeding from the incisions
    (Dripping from the incisions can be normal for 24-48 hours as long as you can count the drips of blood. If it is a steady stream of blood then contact the vet)
  • Swelling
    (Again this can be normal for the first few days but it should reduce with turnout. If not contact the vet)
  • Something hanging down from the incisions
    (This can be a remnant of the cord or fat from the inside of the horse’s belly or very rarely intestine from the horse’s belly. In any situation, contact the vet)
  • Infection
    (This would normally be seen about a week after the operation. The horse may be lame or off colour or just have a very swollen scrotum. Always contact the vet if you are concerned)
  • Colic

(A horse should NEVER be off colour or colic after a colt castrate) If you are concerned about any of these complications in your gelding ALWAYS RING THE VET FOR ADVICE. After the operation your horse will remain sedated for approximately an hour. The tail bandage can be removed within 2 hours of the procedure. He will be able to eat something when he is properly awake. We usually recommend in hand walking for the same day and turnout can start from the following day. The newly gelded horse should remain separate from mares for 6 weeks. We don’t recommend worming your horse 1 week either side of your colt being gelded. A first tetanus vaccination can be given at the same time as your colt is castrated. The second vaccination will be due in 4-6 weeks time. A tetanus antitoxin injection is always given to give immediate protection against this potentially fatal disease.

Check out our video of our vet Arnie Agnew explaining the procedure and anatomy of a castration by clicking on the link below –

Castration video

Latest News