The miracle of stem cell therapy continues to wow both veterinarians and horse owners as more evidence comes forth to prove how well this revolutionary treatment really works.
Stem cell therapy is possible through the use of equine adult or somatic stem cells, which are found throughout the body. The body uses these cells primarily to repair damaged tissue. Stem cells perform this task by transforming themselves into cell types compatible with the injured area. The mesenchymal stem cell in particular repairs bone, cartilage, fat and fibrous connective tissue.
For use in horses, adult stem cells are usually collected from fat, bone marrow or umbilical cords. The only U.S.-based stem cell company using this therapy on horses, Vet-Stem, Inc., in Poway, Calif., collects stem cells from a sick or injured horse’s fat for use on the compromised area. By using the horse’s own stem cells, veterinarians eliminate the possibility of tissue rejection, which can happen if the cells come from another horse.
Stem cells have been used to successfully treat tendon and ligament injuries in horses, including strains and bows. Some bone fractures have also been treated. When stem cells are injected into an injury site, they turn into normal tissue. This repairs the damage, and doesn’t create scar tissue. Since scar tissue is inflexible, a horse that heals without stem cell therapy often re-injures itself or never returns to its original level of performance.
Recently, stem cell therapy has been used in racehorses with amazing results. Vet-Stem is currently researching return-to-performance results for racehorses treated with stem cell therapy for a variety of injuries, but in the absence of scientific research, anecdotal information includes reports of profound recoveries.
One such example is a 4-year-old Thoroughbred gelding named Blazing Desert. In late 2005, the horse suffered a broken left hind sesamoid along with suspensory injuries during training. Fifteen months after being treated with stem cell therapy, Blazing Desert won his first race back on the track—by seven lengths.
Another racehorse, six-year-old Thoroughbred Greg’s Gold, bowed a tendon in 2005 after making his way to the top of the Southern California sprinter’s circuit. He was laid up for a year before going back into training after receiving stem cell therapy. After 19 months, he won his first event upon his return, a six-furlong race at Santa Anita.
Performance horses have also benefited from stem cell therapy, including Mister Nicadual, a 6-year-old Quarter Horse gelding trained by reining trainer and USET member Tim McQuay. The horse bowed his left front super digital flexor tendon in November 2005, and was treated with stem cell therapy. Within 10 months of the injury, McQuay and Mister Nicadual won an individual gold at the FEI World Equestrian Games. According to Vet-Stem, successes like these are the norm with this type of therapy. The company’s research indicates the following success rates on performance horses treated with stem cells:
• Eighty-nine percent of horses with tendon injuries responded to treatment, including 33 percent that were classified as severe injuries. Seventy-seven percent returned to their prior level of competition.
• Ninety-two percent of horses with ligament injuries responded to treatment, including 79 percent that were classified as chronic. Seventy-six percent returned to their prior level of competition.
• Ninety-five percent of horses with osteoarthritis responded to treatment, and sixty-seven percent returned to prior level of competition.
• Ninety percent of horses with sub-chondral bone cysts and showing lameness responded to treatment. Eighty percent of those horses returned to their prior level of competition.
Leg issues have been the primary focus of stem cell therapy in horses to date, including such difficult conditions as osteochondrosis (OCD) and laminitis. When stem cells are used to treat degenerative joint disease, clinical improvement is typically seen within a few days or weeks. According to Vet-Stem, even chronic cases can experience dramatic improvement.
Bone fractures demonstrate healing about twice as fast as normal fracture healing rates, as long as they are treated within the first 60 days after the injury. With tendons and ligaments, healing time is dependent upon the extent and location of the injury, as well as performance and training demands on the horse after stem-cell therapy. In general, while stem cells improve the rate of healing, the main benefit is the strength and elasticity of the regenerated tendon or ligament.
In addition to treating soundness issues, Vet-Stem is currently exploring other stem-cell uses in horses, including treatment of chronic obstructive pulmonary disease (heaves). “We are working with academic institutions and also with leading veterinary practices to develop additional uses for regenerative cell therapy,” says Michael Dale, chief operating officer of Vet-Stem. “Injuries and diseases that currently have few treatment options are the targets of new research efforts.” As a result, stem-cell therapy could become an important form of treatment in the not-too-distant future.