The availability of horses 20 years old and older on the University of Kentucky’s Maine Chance Farm and on farms in the Lexington area was one of the things that interested David Horohov, PhD, William Robert Mills Chair in Equine Immunology, when he joined the faculty at the Gluck Equine Research Center in 2003.

His interest in older horses was a continuation of work that he began 19 years ago while at Louisiana State University (LSU). That early interest grew from a collaborative research project involving researchers at Rutgers, The State University of New Jersey, led by Karyn Malinowski, PhD. That study focused on the effect of exercise on young and old Standardbreds. While Horohov’s interest was on the effect of exercise on immune function, it was the differences between young and aged horses that caught his attention.

“What we noted was even before they were exercised, there were significant differences between the young horses and older horses in the ability of their immune systems to respond to stimulation,” Horohov said. “So, that piqued my interest. We went on to publish a paper describing these differences. Prior to that paper, relatively little was known regarding immunosenescence (age-related changes in immune function) in horses