Canadian researchers are about to begin clinical trials using allogeneic umbilical cord blood stem cells to treat superficial digital flexor tendonitis or “bowed tendons” in horses.
The goal of the team from the Ontario Veterinary College (OVC) is to develop a readily available treatment to prevent the formation of scar tissue and create good quality tendon tissue to replace the damaged tissues, which are less prone to re-injury.
The research has been partly funded by Equine Guelph and Ontario Equestrian (OE) and its members, who scrapped their membership cards to create the Member Equine Research Fund program in 2017. Instead of spending $1.50 per member on the production of membership cards, the funds were directed to lameness studies resulting in a donation of just over $30,000.
The study team is being led by primary investigator Dr Judith Koenig. “Currently, the re-injury rates reported are between 56 to 75% for superficial digital flexor tendon injuries once the horses return to competition,” Koenig said.
In a pilot study with three horses, it was found that repeated injections of the allogeneic stem cells were very effective and that two of the horses were able to successfully return to racing and the third was able to start a career as a competitive sport horse.
“My hope is that we can develop a treatment that can be available within an hour of taking out of the freezer,” Koenig said.
This treatment uses allogeneic stem cells, which means the stem cells do not need to be from the recipient. These stem cells are collected non-invasively from the umbilical cords of newborn foals and then stored for later use.
The Equinosis Q Lameness Locator, previously donated to the OVC by the Equine Foundation of Canada (EFC) will play an integral role in this study. This system uses micro electric sensors positioned on the poll, pelvis and pastern of the horse to detect subtle signs of lameness.
Koenig said the next challenge was to enrol horses in the study, which requires very tight parameters in order to have meaningful results.
The horses need to be Thoroughbreds in race training who have raced at least three times and incurred an injury to their superficial digital flexor tendon (SDFT) and have sustained lesions that have been diagnosed by a veterinarian. The lesions also will need to fall between specific measurements. The treatment and rehab period is expected to take between eight months to one year. The owners will receive cost incentives for enrolling their horses and following treatment and rehab protocols.
The progress of the horses in the stem cell treatment group will be compared to that of a control group which will be receiving platelet-rich plasma (PRP) injections. PRP is currently a common treatment used in the field for superficial digital flexor tendonitis.
Having more efficient and effective treatment options for superficial digital flexor tendonitis will improve the health of the horse, extend competitive careers, and reduce economic losses. This clinical trial will provide insight into the promising treatment of allogeneic umbilical cord blood stem cells.
Koenig’s team comprises Dr Thomas Koch, Dr Nathalie Coté, Dr Stephanie Nykamp, and graduate student Alejandro Merchan Munoz.