Veterinarians at Rood and Riddle Equine Hospital answer your questions about sales and healthcare of Thoroughbred auction yearlings, weanlings, 2-year-olds and breeding stock.
Question: What are three things you should watch out for on a pre-sale radiograph of a yearling you’re hoping to buy for racing?
Dr. Kathleen Paasch, Rood and Riddle Equine Hospital: After looking at dozens of sale yearlings you’ve narrowed your list down to a handful. Now for the vetting. It would be wonderful if it were as simple as avoiding only three radiographic issues but of course, it’s not that easy. There are far more than three areas of consideration. And, like radiographs, these issues are not often not black and white but infinite shades of grey.
Just as assessment of physical characteristics and pedigrees is subjective, radiographic interpretation (and subsequent recommendations) are also subjective. Generally, we are more tolerant of various radiographic abnormalities in yearlings bought to race as opposed to those for re-sale but there are some lesions that are best avoided. The following are three examples of findings that would make a yearling a poor prospect for racing.
Significant Changes in the Distal Radiocarpal Bone:
The radiocarpal bone is located on the medially (inside) of the middle carpal joint (knee). It bears a considerable amount of weight and stress at speed. A yearling that already has marked changes here is not a good bet to hold up for racing.
Large Stifle OCDs:
Mention the words ‘stifle OCD’ and many will immediately remove that yearling from consideration. However, stifle OCDs come in various locations and sizes and do not all carry the same degree of risk. Multiple graded stakes horses have had stifle OCDs. That said, large OCDs that involve a significant amount of joint surface should be avoided.
Severe Tarsal Arthritis:
Many yearlings have mild and insignificant changes to the lower joints of their tarsi (hocks). However, a foal’s tarsal bones can become irreparably crushed and malformed, leading to performance limiting degenerative joint disease as a yearling/adult.
These examples are in no way a comprehensive list of findings to avoid. They are extreme examples and radiographic findings are rarely so clear-cut.
It is important to note that milder variations of the above may be perfectly acceptable for racing (e.g., small OCDs, mild carpal or tarsal changes). As with other aspects of buying yearlings, radiographic findings often involve a series of compromises. To this end, when purchasing yearlings, buyers should work with a veterinarian whom they trust and who is familiar with their interests and level of risk tolerance.
Dr. Kathleen Paasch received her veterinary degree from Washington State University in 1999 and completed an internship with Rood and Riddle Equine Hospital in 2000. She is now a shareholder and ambulatory veterinarian at the hospital, where she specializes in lameness, diagnostic imaging, and acupuncture.