A way to improve or resolve a condition or diagnosis. This might include resolving the underlying cause or treating the signs of disease (symptomatic treatment).

Cost: Under $100

These cost ranges are approximate and may vary from region to region.
Additional charges may also apply.

YOUR VET MAY Recommend

Castration or Gelding, Routine

Cost: Under $100

These cost ranges are approximate and may vary from region to region.
Additional charges may also apply.


Castration, the surgical removal of a male horse's testicles, is commonly performed to prevent unwanted breeding, and to reduce or lessen stallion-like behavior. On average, a colt is castrated by his second year of age, however castration can be performed from a young age (prior to weaning), to aged stallions. While post-castration complications are rare, they can be fatal so it is very important to recognize them early and keep in good communication with your vet. if there is any question regarding care after castration.

Castration is routinely performed as a field procedure. The procedure can be performed with the horse standing, sedated or lying down under short acting general anesthetic. The method chosen depends on veterinarian preference. I prefer to perform castrations on horses lying down, using short-acting general anesthesia

A routine castration takes 5-10 minutes to perform. I will describe the procedure as I do it, under short-acting general anesthesia. I administer an antibiotic and anti-inflammatory injection first (phenylbutazone). If a horse has not been properly vaccinated for tetanus, then ensuring immunity to that disease is also important.

First the horse is sedated until he becomes unsteady on his feet. Usually 3-5 minutes later, the general anesthetic is given and the colt is guided to the ground (I have them lie left side down). A rope ties the hind limb up and out of the way. The scrotum is cleaned and surgically prepared. A skin incision is made over the lower testicle. The testicle is isolated and the spermatic cord and vessels crushed using an emasculator. The testicle is removed. I usually do not tie off the vessels, but some vets do. The procedure is repeated for the other testicle. Excess scrotum, fat and connective tissue is removed and the incisions are left wide open for adequate drainage. I check for wolf teeth while the horse is down, and remove them if the owner wants them out.

The horse often lies down for another 10-15 minutes while the anesthesia wears off.


You can take an active role in ensuring that a castration is a success. Prior to your appointment and being careful not to be kicked, feel for both testicles in the scrotum before you schedule this procedure.

If you cannot feel both testicles, share that finding with your vet. Your colt may have a cryptorchid (undescended) testicle, and this may necessitate a different and more costly surgical procedure.

Proper aftercare is important as well, so plan to be able to monitor your horse for 7-10 days after the castration to help ensure a successful recovery.

my vet's role


Excessive bleeding (uncommon if the emasculation has been performed correctly) usually occurs the day of the procedure if it is going to occur. Donkeys tend to have larger testicles and testicular vessels than horses. Hemorrhage is more common following donkey castration and some vets tie off (ligate) the vessels to reduce that likelihood.

I prefer to perform this procedure outside of fly season, given that the incisions are left open to heal. Flies introduce bacteria into the wound, increasing the likelihood of infection.

Excessive swelling over the first week usually results from either insufficient exercise, or insufficient drainage from the surgical site.

Infection of the castration site can occur any time within several weeks of the procedure and may result in depression, lack of appetite and swelling.

Evisceration (eventration) is when intestine slips out of the abdomen through the surgical incision. This is a very rare complication that usually happens soon after castration, but can happen later. It is thought to be more common in Warmblood, Draft Breeds, and some gaited breeds.


This procedure should not be performed on horses that are otherwise ill, or on horses that only have one descended testicle (cryptorchid).

your role

Is it working? Timeframe for effect.
A recently castrated gelding can still impregnate a mare with the sperm remaining in its urogenital tract.

Stallion like behavior usually fades within days to weeks. That said, be sure to keep a recently castrated gelding away from mares for at least 30 days. It may take longer for stallion-like behavior to fade in older, experienced breeding stallions.
Questions To Ask Your Vet:
  • Do you have a post-castration care handout for me to review and follow?
  • How can I try to prevent or lessen infection in the incision site?
  • What sort of exercise routine do you recommend?
  • Do you routinely give antibiotics as part of the procedure?

further reading & resources

Author: Doug Thal DVM Dipl. ABVP