While researchers already know that some breeds—such as Welsh ponies and Morgans—are predisposed to developing EMS, these study findings emphasize the importance of strategic breeding decisions. | Photo: iStock

Heritability is a foal’s likelihood of inheriting specific genetic factors from both parents, said Elaine M. Norton, DVM, MS, Dipl. ACVIM, a PhD candidate at the University of Minnesota (UM) College of Veterinary Medicine, in St. Paul.

Equine metabolic syndrome is a complex disorder associated with an increased risk of laminitis (in which the leaflike laminae that suspend the coffin bone within the foot become inflamed or fail and separate from the coffin bone and the hoof wall, allowing the bone to rotate or sink) that includes insulin dysregulation (abnormal insulin responses) and any combination of:

• Increased or regional adiposity (fat deposits);
• Inability to lose weight;
• Dyslipidemia (abnormal lipids, or fat, levels in the blood); and
• Altered adipokine (proteins secreted by adipose tissue) concentrations.

“We expected that the heritability of genetic traits linked to EMS would be about 40%,” said Molly McCue, DVM, MS, PhD, Dipl. ACVIM, professor and interim associate dean of research at the UM College of Veterinary Medicine. “The fact that several traits had higher estimates is surprising and