Conditions or ailments that are the cause of a problem that you see - your observation.

Your vet may diagnose

Proud Cut, Retained Testicular Tissue in Previously Castrated Horse

Synonyms: Retained or Undescended Testicle in a Castrated Horse


In a normal castration, the two testes and the associated epididymis (sperm storage site located next to the testes) are removed.

A gelding is termed "proud cut" if the horse has been castrated, but all or a part of a testis remains after castration. This can happen when one testis has not fully descended into the scrotum (cryptorchid) when the castration is performed. It is considered unethical and improper to only remove one testicle from a stallion.

In this case, this apparent gelding will typically display stallion-like behavior due to the testosterone produced by the remaining testicular tissue. Proud-cut geldings are usually infertile.

If your vet suspects that your horse has a retained testicle, they will use diagnostics, including the measurement of testosterone in the blood, to determine whether this is the case.

Once diagnosed, surgical removal of the testicular tissue (a different procedure than routine castration) is advised.

Note: Some geldings, particularly those gelded later in life, continue to display stallion-like behavior despite complete removal of all testosterone producing tissues during castration.

my vet's role


The prognosis is good with surgical removal of the remaining testicular tissue.

my role

Questions To Ask Your Vet:
  • How do I know this isn't merely a behavioral pattern that persists from before my horse was castrated?
  • What is my recourse, since I purchased this horse understanding that he was a gelding?

Before castrating a horse, your vet should be able to feel both testes in the scrotum. If they cannot definitively feel both testicles, they will not castrate the horse at that time.

Sometimes, both testes are difficult to palpate in younger horses, and your vet may suggest that you wait to have the castration performed later, after the testicles more fully drop. This is unlikely to occur after 18 months of age. Keep in mind that most colts have two testicles present at birth.

The entire testicle and epididymis must always be removed. Even though the epididymis does not produce testosterone, proper castration removes this structure as well.

further reading & resources

Author: Doug Thal DVM Dipl. ABVP