Spontaneous pneumomediastinum in three adult horses

The report describes the diagnosis and management of spontaneous pneumomediastinum in three horses which were presented with acute-onset increased respiratory effort. Pneumomediastinum was evident radiographically without evidence of internal or external trauma. Two horses had no obvious inciting cause and one horse had chronic interstitial pneumonia. All horses developed echocardiographic changes consistent with right heart dysfunction. Radiographic evidence of pneumomediastinum resolved in 14-21 days along with all other clinical abnormalities. Despite the severity of the initial clinical signs, all cases reported made a rapid and complete recovery, suggesting that, as in human beings, spontaneous pneumomediastinum in horses is a benign condition with a good prognosis.