The most common reason for a racehorse being ‘put down’ or euthanised, is it has suffered a catastrophic injury from which there is little hope of recovery. A racehorse is an extremely valuable animal and most owner’s will do everything possible to avoid losing them.
Horses are large, heavy animals, supported by slender legs with each foot supporting around 250 pounds of weight. Leg injuries are extremely common and an owners worst nightmare, in the wild a horse with such an injury would not last long before coming easy prey for any predator.
Young horses suffering minor breaks, such as small fractures or incomplete fractures where a bone cracks under stress but doesn’t break, have a fair chance of recovering as they are not fully grown and their bodies are lighter. Race horses are at risk of suffering traumatic injuries, when they fall, trip, or are kicked by another horse. The terms ‘broken down’ and ‘pulled up’ are often heard on the race course and usually mean the horse has suffered some injury, the jockey then gradually slows the horse down and brings it to a halt to avoid any further damage being done.
When a horse suffers a complete leg fracture they are notoriously difficult to treat and the percentage who survive such an injury is small. As horses have no muscle below the knee or hock joint, the blood flow is restricted to these areas, which often leads to complications in the healing process. A fracture which results in broken skin also carries a very high risk of infection as it will often have been in contact with grass, dirt and manure.
In rare cases treatment is possible but a lot depends on the severity of the injury and the horses temperament. Trying to keep a horse from further injury while recovering is a difficult task. Active by nature, most don’t take kindly to being confined to stables or the use of slings to help bear their weight while the injured leg heals. Ensuring they have adequate pain relief is a real problem, to little and they suffer, to much and feeling good, their inclination is to gallop around.
Treatment can be extremely painful for the horse, and even then, with years of treatment, the leg will never heal completely, leaving the horse with chronic pain. It will never run or jump again, let alone walk properly. That's why many owners and vets think the most humane course of action is to put the horse down.