Although stem cell therapy continues to increase in popularity for treating horse racing injuries, its use bas been based only on experimental data regarding the treatment modality’s efficacy. However, a group of researchers from Great Britain recently published a study examining the effects of stem cell therapy in superficial digital flexor tendons (SFDT, located at the back of the cannon bone, running from the knee/hock to the fetlock) of racehorses at least two years after therapy occurred.

"My research group compared the safety and reinjury rate in Thoroughbred racehorses with naturally occurring superficial digital flexor tendinopathy (disease of the tendon) who were treated with stem cells to data published on horses with the same injury but which were managed using treatments other than stem cells," explained Roger Smith, MA, VetMB, PhD, DEO, Dipl. ECVS, MRCVS, a professor of equine orthopedics at the Royal Veterinary College in the United Kingdom.

Of the 113 horses included in the study, all of which had suffered an SDFT injury and were treated with bone marrow derived-mesenchymal stem cells (i.e., stem cells recovered from bone marrow):

• 98.2% returned to racing; and
• The reinjury rate was 25.7% in National Hunt (similar to steeplechasing) horses and 50% in flat racehorses.

Smith et al. then compared the data they collected to previously published literature on similar injuries treated with traditional methods (such as stall rest, poultices, ice, and wraps)