Use of ultrasound to diagnose diaphragmatic rupture in dogs and cats.

Twenty-one cats and six dogs that presented to a first-opinion clinic with signs of dyspnea and muffled cardiac auscultation received ultrasonography to look for signs of diaphragmatic rupture. The presence or absence of diaphragmatic rupture was subsequently determined on the basis of unequivocal radiographic signs, surgical findings, or necropsy. Consistent findings in animals with diaphragmatic rupture were irregular or asymmetric cranial aspect of the liver and abdominal viscera in the thorax. Accuracy of ultrasonography was 25/27 (93%). One false-negative result occurred in a cat with a chronic diaphragmatic rupture in which adhesions between the liver and lung simulated the appearance of an intact diaphragm. One false-positive result occurred in a dog with an abscess involving the left lung and pleural cavity, which was misinterpreted as the stomach. The results of this study support use of ultrasonography in animals with suspected diaphragmatic rupture.