what is a chestnut on a horse

A chestnut on a horse is a callosity or a hard, callous-like growth on the inner side of the leg above the knee on the foreleg and, if present, below the hock on the hind leg). Chestnuts are formed from small deposits of keratin that gather on the horses leg and feel oily and scaly to the touch, similarly to how a skin callus feels. They are harmless and do not affect the horse, but they can cause some sensitivity to the horse, so its important to pay special care to the area of the chestnut growth while grooming or riding. Chestnuts grow over time, protruding from the surface of the leg, and they never stop growing). Grooming for horse showing may include peeling or trimming the outer layers to give a neater appearance to the leg; they may peel more easily if softened first with baby oil or moisturizer). Chestnuts can range from tiny and flat to large and bumpy, and they can be found on all four legs of most domestic horses, as well as on the Przewalskis horse). However, a few horse breeds are reported to lack chestnuts on the hind legs, including the Banker horse, Caspian pony, and Icelandic horse).