Pneumothorax in horses: 40 cases (1980-1997).
OBJECTIVE
To characterize pneumothorax in horses and to describe clinical signs, diagnostic testing, and clinical outcome of horses with pneumothorax.


METHODS
Retrospective study.


METHODS
40 horses.


METHODS
Medical records of horses with pneumothorax were reviewed to obtain information on signalment, history, clinical signs, diagnostic testing, treatment, and clinical outcome.


RESULTS
Horses developed pneumothorax secondary to pleuropneumonia (17 horses), open wounds of the thorax (9), closed trauma to the thorax (7), surgery on the upper portion of the respiratory tract (3), and surgery involving the thoracic cavity (1); 3 horses had pneumothorax of unknown cause. Clinical signs included tachypnea, dyspnea, cyanosis, lack of lung sounds on auscultation of the dorsal aspect of the thorax, fever, tachycardia, signs of depression or anxiousness, and cough. Radiography and ultrasonography were useful to definitively diagnose pneumothorax. Pneumothorax was bilateral in 47.5% (19/40) and unilateral in 42.5% (17/40) of horses; designation of unilateral versus bilateral was not recorded in the remaining 4 horses. Horses with pneumothorax secondary to pleuropneumonia more commonly had unilateral pneumothorax (64.7% for unilateral vs 29.4% for bilateral; not specified for 1 horse). Horses with pneumothorax secondary to pleuropneumonia were less likely to survive than horses with pneumothorax secondary to other causes (35.3 vs 69.6% survived, respectively).


CONCLUSIONS
Pleuropneumonia is an important cause of pneumothorax in horses. Classic clinical signs of pneumothorax may not be evident. Radiography, ultrasonography, or both may be required for diagnosis. Prognosis for survival is better for horses with pneumothorax not associated with pleuropneumonia.
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Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, New Bolton Center, Kennett Square 19348-1692, USA.
Sweeney
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D000818:Animals; D005260:Female; D006548:Hernia, Diaphragmatic / Q000150:complications / Q000601:surgery / Q000662:veterinary; D006734:Horse Diseases / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D006736:Horses; D008297:Male; D011001:Pleuropneumonia / Q000150:complications / Q000662:veterinary; D011030:Pneumothorax / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000662:veterinary*; D011379:Prognosis; D011996:Records / Q000662:veterinary; D012137:Respiratory System / Q000601:surgery; D012189:Retrospective Studies; D013898:Thoracic Injuries / Q000150:complications / Q000662:veterinary