The sheath is a tube of skin that protects the horse's penis. Smegma or a lubricating secretion fills the inside of the horse's sheath. In the wild, a horse would work out this lubrication naturally through sex, but in a domesticated setting, this secretion tends to build up, forming “beans” within the horse's sheath. Not every horse has this problem, nor is there a consensus on whether or not a sheath should be cleaned. Either as a preventative or reactionary measure, in consultation with your vet, you may decide to periodically clean your horse's sheath. Normally, this cleaning should be done at least every 6 months for a gelding (a castrated male horse) and every year for a stallion (an uncastrated male horse).[1] A male horse's genitalia is very sensitive, so you need to proceed carefully.

Deciding Whether or Not to Clean Your Horse's Sheath

Understand the pros. In general, arguments in favor of washing a horse's sheath focus on hygiene and reducing the chances of infection. Bacteria tend to colonize around the smegma. The exact nature of the secretion and the likelihood of infection vary from horse to horse. No matter what, an excessive build-up can lead to irritation and inflammation in any horse. In turn, the sheath can swell up, which can restrict the horse's ability to procreate or even urinate. Some owners report that excessive smegma actually attracts flies, which carry disease.