Why is my horse over reaching?

Overreaching — when the toe of a hind foot strikes the heel, coronary band, or lower leg of the front foot on the same side — is closely related to forging but distinctly more serious, because where forging produces an unpleasant sound, overreaching produces an actual injury to the front foot or lower leg that can range from pulling a front shoe to causing cuts and lacerations at the heel and coronary band that require veterinary attention. The mechanics of overreaching are the same as forging but more extreme — the hind foot not only reaches the location where the front foot was, but arrives there before the front foot has fully cleared. The factors that contribute to overreaching are therefore the same factors that contribute to forging but present to a greater degree: excessive hind leg engagement relative to front leg breakover speed, a long toe delaying front foot clearance, fatigue affecting the timing of the footfalls, and overall heaviness on the forehand. Speed is a specific contributor to overreaching that distinguishes it from forging. A horse may forge at the trot without overreaching, but at the canter and particularly in jumping — where the hind legs propel the horse forward with significant force and the front feet must clear the ground quickly as the horse lands — the speed and power of the hind leg's forward drive makes overreaching much more likely. Farriery is the most direct and most effective practical intervention for overreaching when the cause is related to hoof geometry. A front foot with a long toe breaks over slowly, giving the hind foot additional time to arrive before the front foot has cleared. Shortening the front toe and rolling or squaring the toe of the front shoe significantly accelerates breakover and reduces overreaching in many horses. Some farriers also address the hind feet — shortening the hind toe or using a squared toe on the hind shoe — to reduce the effective reach of the hind foot. Overreach boots — rubber bell boots that cover the heel and coronary band of the front feet — are the appropriate protective measure for horses that overreach during work, particularly jumping and fast work where the risk is highest. They do not correct the underlying cause but they protect the most vulnerable structures from the injuries that overreaching produces.