Should You Clean Your Horse’s Sheath?

Original Article from AAEP (Feb, 2011)

901_SheathCleaninghorseUntil I read this article from the American Association of Equine Practitioners, I would have said …YES! Now I’m forced to rethinking something that, in the past, I had just taken for granted

The author of the article is Dr. Benjamin Espy who is a specialist in equine reproduction and infertility, practicing in Texas and Kentucky and is on the Board of Directors of the AAEP, so when he says something we’d be foolish not to listen and consider.

According to Dr. Espy cleaning a horse’s penis or sheath is rarely necessary. In fact, the aggressive cleaning methods promoted by many well-meaning horse people often do more harm than good.

Never stand at the back of a horse to clean its sheath – you know what can happen!

Stand at front on the shoulder with your hand on the mane when you clean the sheath - this is a safe place to stand.

Caution: Dr Espy’s opinion is not universally accepted by all veterinary groups and associations. Many believe that cleaning and examining the penis is an essential horse husbandry activity. As with many contentious issues there is usually a middle ground that can offer a balance between opposing ideas.

We have reproduced Dr Espy’s article with minimal editing, and have retained his use of the ‘myth and answer’ format.

Myth 1: Accumulation on the penis is dirty and unhygienic

Male horses are not male humans…they don’t have the same hygiene needs. When a stallion or gelding extends or ‘lets down’ his penis, the accumulation you see is smegma, not dirt. This material is continually secreted and its purpose is to lubricate and protect the penis.

The smegma may vary in quantity and type…from dry and flaky to moist and goopy, but all of it is normal.

Note: Excessive smegma accumulation is extremely rare and usually associated with skin conditions or lesions, like herpesvirus or squamous cell carcinoma. These are commonly located on the penis and need to be diagnosed by your veterinarian.
If your horse has suffered a laceration in the area, has undergone surgery to remove a cancerous growth, has a skin condition from equine herpesvirus or squamous cell carcinoma your vet may recommend a cleaning programme.

Myth 2: All male horses require routine sheath cleaning

The best proof that sheath cleaning is completely unnecessary is the reproductive health of stallions in the wild. These horses, who obviously have never had their sheath cleaned, have conception rates approaching 85%. Domestic stallions, on the other hand, who frequently have their sheaths cleaned (sometimes three or four times a day), average only a 70% conception rate.

Myth 3: Swelling in the sheath and tail rubbing are signs that a horse’s sheath needs cleaning

When a sheath swells, it has nothing to do with the accumulation of smegma inside it. Because the sheath is located on the underside of the horse, it is simply a natural low point where excess fluid is drawn by the forces of gravity. Some time in the paddock, where your horse can move around, will probably get rid of the problem.

Another cause of sheath swelling is parasites. Parasites also make horse’s tail itchy. So if you notice your horse rubbing its tail and it has a swollen sheath, both may be cured by deworming with an ivermectin product.

Note: Older horses may have sheath swelling caused by low protein levels in the blood or liver disease. The swelling is caused by excessive fluid build-up not poor hygiene. If you suspect this is the case call your vet for blood tests.

Myth 4: An unusually large smegma ‘bean’ can block a horse’s urethra

Smegma can accumulate in the depression at the end of the penis (called the urethral fossa). This accumulation is commonly called the ’bean’, and can vary in size from the size of an eraser to the size of a lima bean. No matter how large it is the force of a horse’s urine stream is far too strong to be stopped by any amount of smegma.

Note: If a male horse stands ‘camped out’, with his hind legs stretched out behind him and his back hunched in an uncomfortable position he may be experiencing abdominal pain caused, for example, by colic or ulcers.

Dr Espy’s Conclusion

Not only is sheath cleaning unnecessary, it can often be harmful. The traditional method of poking a hose up into the sheath and scrubbing it and the penis with sponges and antibacterial soap removes the natural protective covering and healthy bacterial population, potentially causing micro-abrasions (small cuts) and sores.

Expect whatever cleaning you do to be short-lived. Normal smegma production will restore the accumulation to your horse’s normal level within a week.

Our Comment: After discussing this article with our vet we feel that there is a sensible middle ground. Our vet agreed that well-meaning horse owners may do significant damage to the delicate skin surrounding the penis and membranes lining the inside of the sheath. By cleaning too frequently, vigorous use of sponges, use of strong chemicals and sticking hoses up inside the sheath, owners can do more harm than good.
Our vet suggested that male horses
do need to be examined at least annually, but to do this the horse needs to ‘drop down’ his penis. This usually requires a mild sedation so that a thorough examination can be conducted, which can eliminate the presence of cancerous growths or skin conditions. At this time your vet can complete a thorough but gentle clean using a very dilute iodine and tepid water solution. Owners can make this part of their annual overall health check and immunisation programme.