Q: Over the years, I’ve had a number of pre-purchase exams done on my horses. I’ve come to realize that one vet will read an X ray and say a horse has arthritis, osteochondritis dissecans (OCD), navicular problems, etc., but when you have a different vet read the same X rays, they will come up with totally different findings. Why is this?        Sue

A: First, it is most important to know something of the discipline in which the prospective horse/buyer is involved. Second, knowledge of the competition history of the horse is very valuable. A young, untrained horse should not demonstrate the mild lesions of wear and tear that an older campaigner could tolerate. OCD in the young, untrained horse might carry a higher level of risk than a similar finding in a trained horse that has lived with the lesion with no ill effects for years. Many of the so-called “changes” are an adaptation to the stress of doing a specific job, and judging the horse based solely on radiographs can be very misleading.

More emphasis needs to be placed on the physical exam, flexions, performance, etc. Knowledge of the discipline is critical for the examiner. For example, certain physical findings might be well tolerated by the show hunter, but would never be acceptable for the prospective racehorse. This is a matter of communication on the part of the examiner in relaying this information.