Mammal Image Gallery
Mammal Image Gallery

Barbaro wins the 2006 Kentucky Derby, seen here. Two weeks later, the Preakness Stakes proved to be his final race. A broken leg would be the end of his career and eventually his life. See more pictures of mammals.

Mike Ehrmann/WireImage/Getty Images

Back in the Wild West, a horse with a broken leg might have spent its final seconds staring down the barrel of a cowboy's gun. In the old days and today, horses are commonly euthanized after breaking their legs because they have a small chance of successful recovery. Researchers are working hard to try and discover new techniques that will improve an equine's chances in the face of a fracture. For now, an easy fix remains elusive.

It's difficult for a horse's leg to heal due to a combination of factors. Their legs must absorb considerable shock as their powerful bo­dies gallop at high speeds. Horses engage in a lot of physical activity, and the consequences of this behavior can eventually lead to deteriorated leg bones and increased opportunities to fall. Another thing to consider is how many leg bones horses have. Out of the 205 bones that make up a horse's entire body, 80 of them are located in its legs. The com­plex system of joints, bones, ligaments, tendons, cartilage, lubricant, laminate and hooves that contribute to a horse's amazing speed can also be the cause of its downfall. What's more, between 60 to 65 percent of a horse's weight rests on its front legs -- that's why most of its injuries occur here.

Many problems can affect horses' legs, like inflammation, osteoarthritis, joint issues and diseases and of course, broken bones. Recovery is further complicated because horses can't lie down the entire time they recuperate. Horses are programmed to stand a good portion of the time -- including while they sleep. As a prey species, they must be ready to flee as fast as possible, which is why horses stay on their toes (or hooves to be more accurate).

Now that we understand why a horse's legs are so important to its overall health and performance, let's find out what happens when those fragile legs break and if they'll have to stare down the barrel of a shotgun.