Sheath problems, especially tumors, are more common than one might expect. For this reason, it is important for horse owners to know how to evaluate and examine a horse’s sheath. Through examination, you may find that it simply needs to be cleaned, or you may find something that you need your vet to evaluate.
It is normal for horses to accumulate sticky, dark smegma within the sheath, and this normally has a pungent smell. An especially unpleasant smell and increased discharge may signal a problem with a horse’s sheath.
Halter the horse. Stand on the left side of your horse at the flank and facing toward the rear end. Make contact with the side of the horse and slide your hand down along the belly to the sheath.
Maintain steady but gentle contact on the outside of the sheath if the horse kicks or moves. Stay near the shoulder to prevent from being kicked. Remove your hand briefly if your horse stops kicking or struggling, and stroke the horse's side, to affirm that there is a release when he stands.
Feel the fatty and loose tissue around the horse’s sheath and up toward the groin. You can often actually feel the penis within the sheath if you try. You should not feel any swelling, lumps or bumps within this tissue. The horse should not act as if your examination is causing them pain.
If possible, try to locate the end of the penis within the sheath. It should feel smooth, with no hard lumps or bumps (a firm bump there might indicate a "bean" or smegma accumulation). Examine the skin of whatever is visible for lumps, bumps, redness, or any other abnormalities.
If you find any abnormalities, including lumps, bumps, swelling, red or inflamed areas or any areas that are painful to your horse during examination, the horse may need a veterinary examination.
Tips for safety & Success
Do not struggle to evaluate or touch your horse's sheath if it appears to cause your horse excess stress or pain. The reason most horses withdraw from contact with this site is a behavioral, training issue.
Like almost anything else we ask of horses, if we are consistent and patient and use basic training principles, we can teach the horse to accept it. If you are not able to get this done, your vet may tranquilize the horse prior to evaluation.