Hoof

The hoof is made up of several structures, primarily the coronary band (where the hair meets the hoof), hoof wall, insensitive laminae, which connect the hoof wall to the underlying coffin bone, the frog and the sole. The hoof wall-the outer covering of the hoof-is comparable to the human fingernail; it grows yet has no nerve endings. The insensitive laminae of the hoof wall interlock with the underlying sensitive laminae, which carry blood to warm the foot and to nourish its growing tissues. When a horse puts weight on a hoof, the hoof wall expands slightly as it becomes weight bearing and contracts when the weight is lifted.

The hoof wall grows downward at a rate of about ¼-inch a month. Excess wall is trimmed by a farrier to maintain the balance of the foot and to minimize stress on the bones, ligaments and tendons of the leg. Therapeutic trimming and shoeing are sometimes used following an injury to reduce stress in particular area. Some conformational faults can be helped by corrective trimming if it is performed early enough in the horse’s life.

The weight of the horse is transmitted through the two layers of laminae to the third phalanx or coffin bone, which is similar in shape to the hoof wall. On the undersurface of the hoof is a V-shaped structure called the frog. The frog is easily seen when the horse’s hoof is picked up; the point of the V-shape is toward the toe and the two legs of the V lie near the horse’s heel. The soft, elastic qualities of the frog allow it to absorb shock and store moisture for the rest of the hoof.

The sole is the tough covering underneath the hoof, which protects the sensitive structures inside the hoof. Not intended as a weight-bearing structure, the sole is slightly concave.