Objective: To describe the indications for, complications arising from, and outcome of horses that had standing lateral thoracotomy for pleural or pericardial disease.

Study Design: Case series.

Animals: Horses (n=16).

Methods: Medical records (January 1990–December 2008) of sedated standing horses that had lateral thoracotomy were reviewed. Clinical and surgical findings, perioperative and short-term complications were recorded. Long-term (>6 months) outcome was determined through telephone conversations with owners and veterinarians.

Results: Mean (±SD) horse age was 6.6±5.3 years (range, 1–15 years). Thoracotomy was most commonly for treatment of recurrent or chronic pleural infection (94%). Anaerobic bacteria were frequently isolated from pleural effusion associated with pleuropneumonia (63%). Right lateral intercostal thoracotomy was performed in 13 horses (82%); intercostal muscle myectomy in 5 horses; and rib resection in 1. Perioperative complications were hemipneumothorax (2 horses) and short-term complications included cellulitis and abscessation of the thoracotomy site (6 horses). Fourteen (88%) horses survived to discharge and 46% of horses that survived returned to their previous level of athletic activity.

Conclusions: Lateral thoracotomy is well tolerated by standing sedated horses with minimal perioperative and short-term complications.

Clinical Relevance: Standing lateral thoracotomy should be considered for the treatment of complicated pleuropneumonia in horses.