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Measuring Tendon Healing in HorsesBy Kentucky Equine Research Staff · February 10, 2017

Soft-tissue musculoskeletal injuries, such as bowed tendons, usually dictate months of stall rest and turnout in small pastures. Horses with tendon injuries all too frequently suffer reinjury if they resume athletic activity too soon, forcing owners to start the recovery process over. Human athletes also suffer tendon injuries, but unlike equine veterinarians, physicians have several techniques to assess tendon healing and help decide when to return to competition. One such technique is referred to as sonoelastography.

Tendons heal by laying down scar tissue rather than replacing highly specialized tendon fibers. Scar tissue produced during the initial healing phase is soft and elastic but becomes increasingly firmer as it remodels in an attempt to replicate normal tissue. The healing process typically takes about nine months.

Ultrasonography not only helps identify the location and size of the tendon injury but is also used to assess healing. Within a few months of the injury, though, standard ultrasound imaging cannot decipher between healthy and injured tendon tissues, making it challenging to know when the tendon is healed and when the horse can resume work.

Sonoelastography involves manually compressing the tendon with a standard ultrasound probe to measure the firmness of the tendon in various locations. The images generated during tendon compression are subsequently converted to colored images that reflect firmness. For example, red denotes soft tissues, yellow signifies tissues of intermediate firmness, and green and blue represent the firmest, least elastic tissues. These images, called elastograms, provide a picture to help guide veterinarians and owners through a horse’s recovery, avoiding premature return to work and reinjury.

The feasibility of sonoelastography in horses was recently demonstrated in a small study* of racing Thoroughbreds with naturally occurring tendon injuries. Though elastograms could prove extremely valuable in the management of career-limiting injuries in athletic horses, more studies are needed.

“Tendon health can also be improved through dietary supplements containing glucosamine and chondroitin sulfate. Typically associated with joint and cartilage health, these ingredients also support soft tissues, including tendons and ligaments,” advised Kathleen Crandell, Ph.D., a nutritionist with Kentucky Equine Research (KER). Try KER•Flex, which contains 10,000 mg of glucosamine and 2,000 mg of chondroitin sulfate per serving, to maximize both tendon and joint health for your horse. In Australia, look for Glucos-A-Flex for joint and soft tissue support.

DuraPlex, a scientifically proven vitamin and mineral product, is another supplement designed for horses that require extended periods of stall rest due to tendon injury or other lameness. DuraPlex helps prevent loss of bone density due to inactivity. Australian horse owners should try Bone Food Plus.

*Tamura, B. T. Nukada, T. Kato, et al. The use of sonoelastography to assess the recovery of stiffness after equine superficial digital flexor tendon injuries: a preliminary prospective longitudinal study of the healing process. Equine Veterinary Journal. In press.