The Down and Dirty on Horse Sheath Cleaning

Updated December 15, 2023 | By: Jamie Whittenburg, DVM

Many riders and owners are told they should clean their horse’s sheath once per month. However, regular sheath cleaning is rarely necessary for most horses. In fact, cleaning a horse’s sheath carries some risk of both injury and infection.

Here we’ll dive into the nitty gritty details for proper care, prioritizing the health of your male horse’s sheath. If you are unsure whether your horse needs his sheath cleaned, please ask your veterinarian for advice.

Gelding and Stallion Sheath Anatomy

Geldings and stallions have a penis and sheath. The sheath, anatomically referred to as the prepuce, is the covering of skin and fat that protects the penis. The male horse typically has his penis retracted up into the sheath most of the time.

The penis can be seen protruding out of the sheath when the horse urinates, is very relaxed, and when sexually excited. Upon sexual excitement, the penis fills with extra blood, and the muscles holding it up in the sheath relax, allowing the penis to protrude from the opening of the sheath.

Sebaceous glands within the sheath produce sebum. Sebum combined with dirt, oils and dead skin cells create a thick, waxy, and flaky material known as smegma. Smegma acts as a lubricant that allows the penis to retract and extend from the sheath and is a protective covering for the skin. It normally accumulates inside the sheath, on the shaft of the penis, and in the depression at the tip of the penis (called the urethral fossa).

Smegma that accumulates in the urethral fossa may form hard, dense lumps commonly referred to as “beans.” It is normal for smegma to vary in color from dark grey to yellowish.

Is Horse Sheath Cleaning Necessary?

Over the years, as we have learned more about horses, anatomy, and the delicate balance of bacterial flora present, the recommendation from veterinarians about frequently cleaning a male horse’s sheath has changed. Still, there are horses who require sheath cleaning. Due to the varying amounts of smegma produced by different horses, it is impossible to give a “one size fits all” recommendation. The most important thing to remember is that we must strive not to do any harm.

Every horse owner wants to take great care of their horse, and many believe that frequent sheath cleanings are part of that. However, evidence suggests that many horses never need their sheath cleaned.

Wild horses, for example, never have their sheaths cleaned and seem not to suffer any detrimental effects. There is even evidence to suggest that wild horses may have higher conception rates [1] than their domestic counterparts, though this is likely multifactorial in nature.

Ask the Vet Video - Does a horse's sheath need to be cleaned?

Safety First

If it is determined by your veterinarian that your horse requires sheath cleaning, whether there is a large amount of smegma present or the horse is having urinary difficulty, safety for both you and your horse is essential. Horses that are not used to the procedure may react fearfully and bite or kick.

Some veterinarians may recommend that they perform the sheath cleaning procedure on your horse. Based on your horse and who is performing the sheath cleaning, your veterinarian may recommend a mild sedative. Owners should not administer medications to their horses without the instruction and observation of their veterinarian. Safe sedation will relax the horse and reduce the potential for injury to both the horse and the owner.

Sedation will also allow the male horse to relax the muscles that retract the penis, which will cause the penis to extend and be much easier to inspect and clean. Further, sheath cleaning is a perfect opportunity to inspect your horse for any abnormal bumps or sores.

How to Clean a Horse’s Sheath

It is imperative always to go slowly, be gentle, and use warm water. Take care to treat the tissue and skin gently to not traumatize the skin barrier and introduce bacteria.

Some smegma accumulations can be easily cleaned just with your hands. You can wear disposable gloves during the process as well. You may also use a damp cloth or sponge and a small amount of warm water, if needed, but avoid scrubbing.

If the accumulation is severe, you may need to mix a gentle, horse-safe soap with warm water in a bucket and use a cloth or sponge to softly clean the urethral fossa and interior of the sheath. There are several reputable sheath cleaning products available that are specifically designed to assist in the sheath cleaning process with non-irritating formulas. Always make sure to read the products instructions and thoroughly rinse to ensure no residue is left behind. A small amount of mild, unscented horse-safe soap that’s diluted in warm water can also be used.

What NOT to Do When Sheath Cleaning

There are several things to remember when cleaning a male horse’s sheath:

• Never forcibly pull on the penis to force it to extend. This is not only uncomfortable for the horse but may result in penile injury as well.
• Be as gentle as possible to not damage the skin barrier of the penis or the inside of the sheath. Do not scrub clean.
• You should never spray water via a water hose directly up into the sheath.
• Avoid using too concentrated soaps that will irritate the skin, strip it of its natural skin oils, and potentially lead to an infection.

Misconceptions About Sheath Cleaning and Hygiene

Over the years, some misconceptions regarding the need to clean a male horse’s sheath have circulated amongst the equine-loving community. Most dangerous is the blaming of a “dirty sheath” or excessive smegma accumulation for medical issues such as a swollen sheath or tail rubbing.

If your horse has a swollen sheath, there is a medical condition that needs to be addressed, and it is likely not due to the sheath being dirty. In this situation, do not clean the sheath and call your veterinarian as soon as possible.

If your horse is seen rubbing its tail as if it is itchy, it is often caused by parasites, not a dirty sheath. Your veterinarian can advise you on which products are appropriate as dewormers for your horse and can also do fecal testing, if necessary.

A third issue often mistakenly attributed to a “dirty sheath” is a popping or groaning sound that comes from the sheath when the horse is exercising. This sound is often referred to as the “gelding noise.” Typically, this noise is heard when the horse is extending its stride and is thought to be a result of tense abdominal muscles, which cause air to be sucked into the sheath. This noise is normal for male horses and does not indicate the need to clean their sheath.

Evidence-Based Reference

1. Wolfe, Michael L., et al. “Reproductive Rates of Feral Horses and Burros.” The Journal of Wildlife Management, vol. 53, no. 4, 1989, pp. 916–24. JSTOR.