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What Is a Proud Cut Horse? Its Cause, Symptoms, and Facts

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Our neighbor invited us over to check out a horse he recently bought. My grandson was especially curious because he heard the horse was “proud cut” and wasn’t exactly sure what to expect.

Proud cut” horses are geldings that express stallion-like behavior. This condition is typically caused because both stallion’s testis and the entire epididymis, the duct behind the testis where sperm is stored, were not removed during castration. These horses continue to produce testosterone.

“Proud cut” is applied broadly, and frequently it’s misused. There can be other factors besides an incomplete castration that leads to the gelding’s odd behavior.

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A Proud Cut Horse

A horse is considered “proud cut” if it’s been gelded but continues to act like a stallion. There could be a few reasons for this phenomenon, but before we dive too deep into “proud cut,” let’s look at the gelding process.


A gelding is a male horse that’s been castrated. Castration is the removal of the testicles and their supporting structures, such as the spermatic cord and epididymis.

Horse castration is used to control breeding and reduce aggressive behavior. Horses of inferior bloodlines are the most likely candidates for castration.

Colts are customarily castrated while young; some as early as three months. Younger horses typically have fewer complications and recover quicker than older horses.

However, you never want to castrate a horse before both its testicles have entirely dropped into its scrotum. But if you wait too long, you run the risk that castration won’t stop the stud-like behavior.

Geldings are typically much easier to handle and train, so if a horse is not a stud prospect, owners castrate them. Even horses with good bloodlines are castrated if they are too hot for their purpose.

We bought a young thoroughbred stallion with excellent breeding to race. Once our horse was old enough to start training, he wouldn’t focus. He was so distracted by fillies and mares that he wouldn’t load into a starting gate.

If he was ever going to race, he couldn’t remain a stallion; he had to be gelded. So we elected to castrate him, and after the procedure, he started training properly and became a winning racehorse.

The castration process

Castrating a horse is not complicated, and, in days past, horse owners often performed the procedure. I remember my grandfather castrating horses on his farm. Today it would be odd for someone other than a veterinarian to perform a horse castration.

The typical steps of castrating a horse:

  • The veterinarian administers a sedative to the horse, and the animal lies down.
  • After he is lying peacefully, the veterinarian cleans the surgical site thoroughly with an antiseptic.
  • The surgeon makes an incision through the scrotum, and the testicles are exposed.
  • The blood vessels above the testicles are clamped off,
  • Both testicles and the associated structures are removed.
  • Sometimes stitches are applied, but stitches aren’t always necessary.

If, after castration, a horse continues to display signs of stallion-like behavior, it is likely due to a failure to remove both testicles, and the horse is still producing testosterone.

proud cut,

“Proud cut” and stallion-like behavior

Expected stallion behavior is attempting to mount mares, screeching at other horses, fighting, erections, and aggressive behavior towards humans and other animals. These traits are directly related to testosterone.

Testosterone plays a significant role in the behavior and physical features of animals. Its testicles produce almost all of the testosterone in a stallion. So it logically follows that by removing the testicles, the stallion behavior should stop.

However, even though testosterone production is halted, some learned behaviors may continue, such as mounting mares and aggression. These exploits are more common in stallions castrated later in life than in horses gelded at a young age.

Picture of a two year old thoroughbred in training

Is “Proud Cut” a myth

As explained earlier, geldings displaying stallion-like behavior are considered “proud-cut” horses. The standard theory is that the veterinarian didn’t cut out the entire testosterone-producing structure during the castration procedure.

But, was the castration a failure, or is the “proud cut” theory a myth. If the surgeon failed to remove either the testes or an associated structure, the horse theoretically could continue to produce testosterone.

The “proud cut” theory has some validity, especially in horses that went through the gelding procedure young. Remember, we mentioned that it’s essential to wait until a stud colt drops both its testicles before castration.

If a stud has a testicle that hasn’t dropped before castration, it’s possible it was left in the horse and is still producing hormones. Testicles that don’t descend even after a horse reaches advanced age is called a cryptorchid testicle.

The word cryptorchid is Latin for “hidden testes.” A cryptorchid can be challenging to locate. It could be found anywhere from the abdomen to the inguinal canal, which is the passageway to the scrotum.

Picture of a young thoroughbred stallion.

If you suspect your horse has a retained testicle, ask your veterinarian to run a blood test to check for testosterone production. In successfully gelded horses, testosterone levels should be very low.

This non-invasive test will determine if a horse has a retained testicle producing hormones.

If, however, the test comes back negative, then your horse is displaying learned behavior. With patience and proper training techniques, a horse acting on learned behavior can rehabilitate.

Below is a YouTube video that shows a horse demonstrating “proud cut” behavior.


Why would you proud cut a horse?

You would not intentionally proud cut a horse. During the gelding procedure, a vet intends to remove both testicles and all of the supporting structures. However, sometimes they don’t do a good job.

Can a proud cut horse breed?

No. Generally proud cut horses are infertile. You may see one tease mares, gain an erection, mount, and even ejaculate, but they are incapable of reproducing.

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