University of Wisconsin researchers have shown that certain forelimb characteristics in the growing foal are associated with higher birth weights, and a foal’s carpal (knee) conformation is associated with the carpal conformation of both of its parents. Additionally, they implicate both genetics and the environment in the forelimb conformation of a Thoroughbred foal.

“Forelimb conformation is a topic often discussed among veterinarians and trainers and its potential impact on athletes, but there is little scientific evidence to go along with anecdotal theories as to the origin of these conformational flaws, and which horses are at risk to develop them,” said Scott Leibsle, DVM, who presented the study findings at the 2005 AAEP Convention in Seattle, Wash., on Dec. 6. He and his co-authors aimed to identify factors that might contribute to or influence conformational development.

“The ultimate goal here is to try and maximize the athletic potential of each horse, with us as veterinarians intervening as minimally as possible,” Leibsle added.

The authors recorded the conformation changes (subjective measurements) of foals every 30-60 days until the foals reached 18 months of age and were sold at the yearling sales. They recorded body weights and noted whether the knees were straight, knock-kneed, offset, or turned out. Fetlock conformation was graded as straight, inwardly rotated, or outwardly rotated. The authors also graded the parents’ conformation whenever possible