There are several reasons. Horses develop problems in their hooves if they don’t move around enough or are forced to put weight on only 3 legs. You can think of their hoof as a giant fingernail, and the bone behind it is shaped like a wedge pointing forwards and towards the ground. Too much pressure on the other 3 hooves can cause severe pain, swelling, and separation of the bone from the hoof. In severe cases the bone in the hoof can puncture through the bottom or separate from the top.
In France, Peyo, a 15-year-old stallion, often comes to comfort and soothe terminally ill patients at the Techer Hospital in Calais. The horse always chooses which patient he wants to see, kicking his hoof outside the door
Peyo was originally trained to take part in equestrian shows, but his handler Hassen Bouchakour began to realize his horse had a different calling. After shows, Peyo would pick people out in a crowd and stay close to them. Bouchakour later realized that he was instinctively choosing people that were sick—either physically or mentally. The trainer gave up his career as a showman and decided to embrace Peyo’s special gift in order to help those who need it. Today, Bouchakour works with a therapeutic organization called Les Sabots du Coeur (the clogs of the heart), which is conducting a study of Peyo’s extraordinary abilities.