An 8-year-old Belgian mare presented to Cornell’s Equine and Farm Animal Hospital following a 12-day history of progressively worsening fevers, dry cough and anorexia. Clinical signs developed after an episode of strenuous travel, and did not resolve with antibiotic or non-steroidal anti-inflammatory medications provided by the mare’s referring veterinarian.

The mare presented to Cornell in respiratory distress. Ultrasonographic examination revealed bilateral pleural effusion, pockets of fluid, gas, and fibrin, and atelectasis in both cranioventral fields. She had prominent thrombosis of her left external jugular vein, pronounced cachexia, and was in atrial fibrillation. She was diagnosed with pleuropneumonia and over the next 20 days was managed medically. Eventually, however, her condition necessitated surgical intervention in the form of right-sided thoractomy to remove fibrin and nidi of infection. Post-surgically, her status improved quickly, and she was discharged to the care of her owners.