Horse Castration – What to Expect

Last Updated on February 22, 2022 by Allison Price

Castrating horses is an easy procedure that most people are not familiar with. XLVets Equine’s Beth will explain the process and give you some tips.

After all the winter spent praying for sunshine and warmer weather, it is finally here!

Heather, my colleague, and I were thrilled to have seven castrates booked into our calendar last Wednesday.

Castrating can be hard work even in the best of circumstances, but with four colts left to their own devices, it was definitely exhausting. We needed a shower afterward!

How are horses castrated

Castration of most colts is done under standing sedation. It can also be done in the yard.

We don’t close the incision because it is impossible to keep it sterile during this procedure. Instead, we leave it open for drainage.

This means that we can’t suture blood vessels to stop bleeding. The suture material may become contaminated and cause infection.

Castration of horses with larger blood vessels is more risky and can result in greater bleeding risk. This includes older horses, larger horses, and mares that have been covered.

These horses will benefit from a closed castration that includes a ligature to the blood vessels and skin suturing. This is done in the clinic and under general anaesthesia.

What is the time it takes to castrate a horse.

Routine castrations usually take between 45-90 minutes from beginning to end.

Each horse is checked briefly to ensure they are healthy. We then have two descended testicles, and we heavily sedate them.

We inject them with a painkiller, antibiotic and tetanus-antitoxin.

It’s very important that the horse is handled well and able to feel their owners’ touch.

The local anaesthetic must be administered. This is often the hardest part, and when we get kicked.

Horse Castration


To inject the half of the anaesthetic, we must hold the testicle while simultaneously inserting a long needle through it. This will relax the muscle and numb any discomfort. The second half goes into the skin and they won’t be able to feel the needle.

This must be done both ways. Usually, the horse isn’t happy and gets wiser to it.

After this, the nurses scrub the area while we don our sterile gloves. We then grab a knife and check if we did a good job using the local anaesthetic. ).

We hope that the horse doesn’t feel it, and stays still as we remove all layers to the testicle.

The blood vessels, spermatic duct, and connective tissues are then separated.

The emasculators are used to clamp the two pieces separately. This is the part that makes the crunching sound, making the boys cross their legs!

We use the emasculators to clamp the blood vessels and cut the tissues. We leave them on for at most two minutes to allow the blood vessels to clot.

I use small forceps to make it easier for me if the blood vessel begins to bleed again. However, this is a personal preference.

After both sides have been completed, I make sure there isn’t any bleeding and then take out the forceps.

You should be able to count the blood drops. If they are too fast to count, you will need to call us back.

To prevent further bleeding, I recommend that you rest for 24 hours and then do gentle exercises to reduce swelling and decrease the chance of infection.

What are the potential risks?

A Newmarket-based major equine hospital found that standing castration can cause serious complications.

It can include minor bleeding, skin infections, and major infections.

Castrates are nerve-wracking for me as a vet student. This is especially because owners tend to view it as a routine procedure and thus a low-risk procedure.

Even if everything goes well, it’s possible for your patient to be unlucky or develop a problem. This can lead to unhappy owners.

Castrations under general anaesthesia had a lower 6% complication rate, but they were three times more costly. This is definitely a disadvantage.

Although I do hope that I have not completely terrorized anyone with whole colts, it certainly makes for interesting food for thought.

Allison Price
Allison Price

I’m Allison, born and raised in San Diego California, the earliest memory I have with horses was at my grandfather’s farm. I used to sit at the stable as a kid and hang out with my Papa while he was training the horses. When I was invited to watch a horse riding competition, I got so fascinated with riding!