Very large and important vessels run down the backs of the pasterns right under the skin. The arteries (carrying blood away from the heart) are under high pressure. They are paired: one inside (medial) and one outside (lateral) and they supply blood to the rear of the hoof and the sole.

Because of their location, injury to these vessels is fairly common. When one is cut, it bleeds severely. Blood may spurt several feet, and you can often hear it hiss with pressure. If both digital arteries are cut, as sometimes happens, the blood supply to the foot can be threatened.