Health & Wellness

Bone Marrow Derived Stem Cell Therapy for Ligament and Tendon Injuries in Horses

Robert K. Schneider, DVM MS
McKinlay & Peters Equine Hospital – Spokane, Washington

Tendon and ligament injuries are common in performance horses. Athletic horses are asked to perform at high speed, make sudden changes in direction, jump over obstacles, or make repetitive movements that could increase strain on the ligaments and tendons that support their joints. It is not surprising that these important weight-bearing structures are injured because they are frequently stretched beyond their biomechanical limits when the horse is performing. Tearing of the fibers in the ligament or tendon results in inflammation, swelling, pain, and lameness that takes the horse out of performance. The injury can be career ending for some horses.

Treatment involves putting the horse through a rest and rehabilitation program that allows time for the tendon or ligament to heal. There is a new treatment available for horses with these injuries. This treatment uses stem cells that are obtained from the horse’s bone marrow, cultured in a laboratory, and then injected back into the injured tendon or ligament. I have used this treatment in more than 300 horses with serious injuries to a tendon or ligament. The successful results in these clinical cases and research studies on stem cells make this the most promising new treatment currently available for horses with tendon or ligament injuries.

The treatment involves taking bone marrow from the sternum between the front legs of the horse. This is accomplished with the horse standing, sedated, using local anesthesia. The bone marrow is aspirated through a large needle that is placed into the sternum. The bone marrow is then shipped overnight to the Advanced Regenerative Therapy (ART) Laboratory in Fort Collins, Colorado ( Stem cells are isolated from the bone marrow and cultured to greatly increase the number of stem cells. This process takes 2 to 3 weeks, then the cells are frozen and shipped overnight back to the equine hospital. Usually 10 to 20 million cells are injected into the injured area in the tendon or ligament. More cells can be cultured when necessary. The cells are thawed and injected into the injured area of the tendon or ligament using ultrasound guidance under general anesthesia. General anesthesia is necessary to insure precise accurate injection into the injured area of the tendon or ligament.

Rest and rehabilitation is still an important part of treatment for horses with tendon or ligament injuries. Using stem cells does not speed up the healing process, but improves the quality of healing. The mechanism for how these cells work is not clearly understood, and is the focus of much current research.

Figure 1 has ultrasound images from a horse with an injury to the superficial digital flexor tendon (bowed tendon) that was treated with bone marrow derived stem cells. The image on the left shows the black hole within the tendon that is the result of fiber damage. The image on the right is a followup ultrasound taken four months after treatment with bone marrow derived stem cells. This is one example of the healing that we have observed using this treatment.

I have been a veterinarian treating lameness problems in performance horses for more than 35 years. I know how these injuries heal when treated with rest alone; bone marrow derived stem cells are doing something to improve healing in horses. There are a large number of horses with severe or reoccurring tendon or ligament injuries that have returned to performance after bone marrow derived stem cell treatment that would not have returned with just rest. Based on the successful results in a large number of horses provides increasing evidence that the treatment is improving healing in tendon and ligament injuries.

In addition to our experience with a large number of clinical cases, we have also evaluated this treatment in an experiment model of ligament injury in horses. In this study, an injury was created in the suspensory ligament in both rear legs. One of the legs was treated with bone marrow derived stem cells while the other leg was not treated. These horses were followed over a six month period while they healed. In all six horses evaluated in the study, the ligament that received the bone marrow derived stem cells healed better than the ligament that was not treated. This study is soon to be published in a veterinary medical journal.

There is a wide variety of treatments currently available for horses with tendon and ligament injuries. Many of these lack scientific and clinical evidence that they are effective in improving healing. There is increasing clinical and scientific evidence that bone marrow derived stem cell therapy improves healing of a tendon or ligament injury in horses. More information and a short video about stem cell therapy in horses is available at This treatment should be considered in performance horses with a serious tendon or ligament injury.

Robert K. Schneider, DVM MS

Jed McKinlay, DVM • Bob Peters, DVM
Misty Parker, DVM • Robert K. Schneider, DVM
509-928-MPEH (6734) • Email:

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