About Us

When it comes to providing reliable and accurate appraisals, John Donaldson and Ryan Mahan are among the most experienced evaluators of bloodstock in the Thoroughbred industry. Both career horsemen, they joined together in 2003 to form Mahan & Donaldson, LLC, a leading Thoroughbred appraisal company.

John attended California Polytechnic College and the University of Arizona while studying veterinary science, genetics, animal nutrition, animal physiology, horse shoeing, breeding improvement, and horse and animal science.

His 45-plus years of hands-on involvement with Thoroughbreds, both as an owner and consultant, began as a veterinary assistant and polo groom in England. From 1979 to 1982, John was employed by Bloodstock Research Co. in Lexington, Kentucky. His responsibilities included buying horses, mare matings and performing conformation evaluations for appraisals.

Since 1982, John has served the Thoroughbred industry as an appraiser and consultant to leading owners and breeders on matters related to buying, selling and breeding.

John also conducts annual yearling inspections for both Fasig-Tipton and The Canadian Thoroughbred Horse Society sale companies.


Growing up in central Kentucky,
Ryan Mahan considered following his stepfather, the well-known equine surgeon, Dr. Robert Copelan, into veterinary medicine. Instead, he finds himself in the auction stand at the leading Thoroughbred sales in the world.

Ryan began his career at Keeneland in 1977 as a bid spotter. He then spent several years as chief announcer before being promoted to auctioneer in 1981.

In 2001, Ryan succeeded the late Tom Caldwell as Keeneland's Senior Auctioneer. That same year, Ryan travelled overseas to serve as head auctioneer for the Piaget Hong Kong International yearling auction held at the Hong Kong convention and exhibition center.

Ryan also serves on the Keeneland inspection committee for the September yearling sale and is the chief auctioneer for Barretts Equine Ltd., the Ocala Breeders’ Sales Company and the Canadian Thoroughbred Horse Society sales.