Peritoneopercardial Hernias in Dogs and Cats

Peritoneopericardial hernias (PPH) are an unusual sub type of diaphragmatic hernias. PPH occur secondary to incomplete separation of the diaphragm from the pericardium during embryogenesis, and are considered to be a congenital defect.

Many PPH are discovered as an incidental finding during routine thoracic and/or abdominal radiographs.Typical findings include  enlargement of the cardiac silhouette and the presence of a soft tissue mass near the heart that is continguous with the abdomen. If herniation of abdominal viscera has occurred, then bowel loops and/or liver can be seen adjacent to the heart on radiographs and sonogram. Because the thoracic cavity is not compromised, pneumothorax is not a typical finding and dyspnea is rarely observed.

Surgical repair is via an abdominal incision.Typically, the diaphragm does not require separation from the pericardium prior to closure. Surgery may be complicated by the presence of adhesions between abdominal viscera and the heart/pericardium. Surgery is curative and generally carries a favorable prognosis if postoperative complications do not occur.