The examining veterinarian needs to determine whether or not it is essential to radiograph the hocks as part of the purchase exam. His or her decision is most often based on the type of horse that is being purchased and the intended use of that individual. Certain types and uses of horses may predispose them to potential hock problems, and therefore it is useful to be aware of any underlying problems that might interfere with the horse's future soundness.
Performance horses such as Hunters, Jumpers, Dressage Horses, and Combined Training Horses tend to have problems with their hocks, and therefore purchase exam radiographs could be extremely useful. Specific breeds, particularly Warmbloods, have a higher incidence of Osteochondritis Dissicans (OCD) lesions in their hocks, and radiographs would be useful in determining the presence of these lesions.
In addition, it is the veterinarian's responsibility to try to uncover the "seeds of disease" that might be present in a horse that is being considered for purchase, and, based on those findings, to determine the probability of a potential soundness problem in the future.