If the defect (hole) in the part is small enough or the path length for the leak is long enough, it will be almost impossible for the fluids to flow through the hole (leak). The fluid properties that affect flow are pressure, temperature, and viscosity.
Though the answer seems to be correct, but when taken from that perspective, one will not keep focused on the real reason. The main reason why we shoe horses is for work, which then determines the style and the type of shoeing for the individual working horse. Various types of historical horseshoes.
Today, most horse training is geared toward making horses useful for a variety of recreational and sporting equestrian pursuits. Horses are also trained for specialized jobs from movie stunt work to police and crowd control activities, circus entertainment, and equine-assisted psychotherapy.