AAEP Convention 2005: Forelimb Conformation and Race Performance

Straight conformation in the forelimb doesn't necessarily beget a more successful racehorse. This is what a research group from the University of Wisconsin's School of Veterinary Medicine discovered in a recent study. However, the group also determined that certain forelimb deviations have a negative effect only on horses' 2-year-old race records.

"Conformational deviation in the young Thoroughbred is extremely common, and as veterinarians, we're often asked to look at these horses and make evaluations and predict performance and injury," said Joseph W. Morgan, DVM, at the 2005 American Association of Equine Practitioners Convention on Dec. 6, 2005. He explained that prior studies showed associations between conformation and injuries (www.TheHorse.com/emag.aspx?id=4986), but until now, there was no conclusive data evaluating racing performance and forelimb conformation.

Two teams of two experienced veterinarians evaluated 2-year-old Thoroughbred racing prospects from the front and side as they stood squarely, then as they were walked. The teams graded the carpus (knee) as straight, valgus (knock-kneed), offset, or turned outward. Fetlocks were graded as straight or having inward or outward rotation. Morgan combined this information with workout data, sale prices, and racing records up to the horses' 4-year-old year to determine the effect of conformation.
Morgan and his colleagues found that duringthe 2-year-old year, horses with multiple mild knee deviations (i.e., more than one of the grades above, such as offset and turned outward) were more likely to start than horses with only carpal valgus (knock knees) or only outwardly rotated knees. So according to this study, neither carpal valgus alone nor outwardly rotated knees alone are desirable in a 2-year-old racing prospect.

Carpal conformation deviation only had a negative effect on the 2-year-old race record and did not affect any later ability. Morgan summarized, "Horses can live with some conformational faults and still perform well; the importance of straight forelimb conformation is overemphasized.

"There are still a lot of questions to be answered about the association of conformation and racing," Morgan added. "I think we need to look at larger numbers and different sales, and see if these associations still hold true."

About the Author

Stephanie L. Church, Editor-in-Chief

Stephanie L. Church, Editor-in-Chief, received a B.A. in Journalism and Equestrian Studies from Averett College in Danville, Virginia. A Pony Club and 4-H graduate, her background is in eventing, and she is schooling her recently retired Thoroughbred racehorse, Happy, toward a career in that discipline. She also enjoys traveling, photography, cycling, and cooking in her free time.

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