Atypical laminitis after orthopedic surgery in eight horses

A retrospective study was carried out to investigate the prevalence and causes of laminitis affecting limbs other than the contralateral healthy limb after orthopedic surgery in horses. Of 3,500 horses referred for orthopedic surgery at the Equine Clinic, Vetsuisse-Faculty, University of Zurich, between 1992 and 2007, eight horses that developed laminitis in one or more limbs, but not primarily the contralateral limb, were identified. The reasons for referral were synovial space infection (n = 4), pastern joint arthrodesis (n = 1), fracture of the central tarsal bone (n = 1), bilateral stifle osteochondrosis (n = 1) and luxation of the superficial digital flexor tendon (n = 1). Postoperative complications included infection of the surgery site (n = 1), severe postoperative pain (n = 2), postoperative myopathy (n = 1), urticaria (n = 1) and cecal impaction (n = 1). The administration of analgesics was discontinued eight days after surgery because of urticaria in one horse and one day after surgery because of cecal impaction in another horse. Seven of the eight horses were euthanized because of severe laminitis. Elimination of infection and effective postoperative analgesia appear important in the prevention of laminitis. Severe postoperative pain should be prevented with adequate, continuous and multimodal pain management. It should also be noted that laminitis may occur in response to excessive weight bearing in limbs other than the contralateral limb after orthopedic surgery.