Horse Side Vet Guide ®

Equine Health Resource

Sheath Feels Thick & Lumpy

Code Yellow - Contact Your Vet at Your Convenience for an Appointment

Code Yellow - Contact Your Vet at Your Convenience for an Appointment

  • If the results of the Whole Horse Exam (WHE) suggest the horse is otherwise normal.

Your gelding’s sheath feels thickened, irregular or lumpy.

The normal equine sheath produces smegma, a fatty and pasty secretion. Some accumulation of smegma in a horse’s sheath is normal. Commonly, smegma accumulates into large clumps which can be felt within the sheath as hard knots, even through the outside skin. In most cases, smegma accumulation with some clumping is not harmful, although the development of a large “bean” at the end of the penis can cause problems and should be removed.

Tumors can also develop in this area and can feel similar. In this case, early diagnosis and treatment is preferred for the best outcome. Actual infection of the sheath is rare. Swollen, thickened sheaths are more common in overweight horses.

Assess and clean the horse’s sheath yourself or ask your vet to do it. If the lumps persist after all the clumps of smegma have been removed, then there may be a tumor mass. If you have any questions about the feel or appearance of the sheath, contact your vet.

Periodic sheath cleaning, by a horse owner or especially a vet, encourages visual inspection of the penis and sheath. Problems such as tumors (that affect this region frequently) can therefore be diagnosed and treated early, improving prognosis and lessening treatment costs. Vets typically tranquilize horses for sheath examination and cleaning. This drops the penis and provides much better visualization of the penis and sheath.

Helpful Terms & Topics in HSVGWritten, Reviewed or Shared by Experts in Equine Health

Author: Doug Thal DVM Dipl. ABVP


We're not around right now. But you can send us an email and we'll get back to you, asap.