Antemortem Diagnose einer Herniation des linken Herzohrfortsatzes durch einen partiellen Herzbeuteldefekt bei einem Hund mit degenerativer Mitralklappenerkrankung

A 14-year-old neutered male crossbreed dog was presented for weakness, cough and weight loss. Cardiac auscultation revealed tachycardia, arrhythmia and a grade V/VI left apical systolic heart murmur. Thoracic radiographs showed a large homogeneous soft tissue opacity in close contact with the cardiac silhouette in the left cranioventral mediastinum. Cardiac evaluation showed atrial fibrillation, degenerative mitral valve disease and a dilated left auricular appendage outside the pericardium consistent with herniation through a partial pericardial defect. Seven months after diagnosis, an atrial septal defect secondary to acquired atrial septal rupture was identified. The dog was euthanized thirteen months after initial presentation because of unresponsive clinical signs of congestive heart failure.