Osseous lesion of the calcaneus following the use of shock wave therapy in a horse.

An 8-year-old horse was treated with shock wave therapy for a soft tissue injury but suffered an increased lameness and bone formations a month after treatment. Subsequent treatment with a herbal blister significantly reduced swelling and lameness, which remained improved after six months.

About the Case

• The study presents the case of an 8-year-old horse that was discovered to have a mechanical lameness, rated 2 on a scale of 10, due to an injury to a soft tissue located at the top of the right tuber calcanei, the protruding part of the heel bone.
• The horse was subjected to several diagnostics such as plain radiographs and ultrasonography. The radiographs revealed soft tissue swelling, with no involvement of the bone, while the ultrasonography exposed an excessive amount of scar tissue in and around the affected tendon.

Treatment and Subsequent Findings

• As a treatment approach, extra-corporeal shock wave therapy was applied to the right hock (a joint in the horse’s hind leg), aiming to decrease the amount of scar tissue. However, a month after this therapy, the horse’s lameness grew worse, rated 3 out of 10, and there was a slight increase in the swelling size.
• Radiographs taken revealed new bone formation along the covering of the right tuber calcanei, an ill-defined radiolucent (appearing dark on x-rays) area, and two detached bone fragments. This suggests an adverse reaction to the shock wave therapy.

Second Round of Treatment and Result

• The horse was then treated with a multi-ingredient herbal blister on the swollen site. The blend contained oil of croton, camphor, pine and thyme, turpentine, and cantharides.
• 20 days after the blister application, the swelling had reduced by 50% and the degree of lameness had decreased to 1 on the scale of 10. A clinical reevaluation conducted six months after this round of treatment showed that the lameness degree had remained stable at 1 out of 10, and a flexion test of the limb came back negative, signifying that the horse had maintained its improved condition.