Fibrotic myopathy in the horse.

The case histories of 18 horses with hindlimb lameness attributed to fibrotic myopathy were reviewed. In 14 horses, the problem developed after trauma. In 5 others, it developed secondary to intramuscular injections. Other causes of the lameness were surgery, exertional injuries, and purpura hemorrhagica. Eleven of the horses were treated by resection of scar tissue or by semitendinosus myotenotomy. Postoperative complications included pressure necrosis under quill sutures (9 horses), acute disruption of the skin incision (2 horses), dehiscence of the wound during healing (2 horses), and prolonged hemorrhage from the wound (1 horse). Of the 9 horses that were available for follow-up examination, 1 was free of lameness, 7 had various degrees of improvement, and 1 had no improvement.