Peritoneal pericardial diaphragmatic hernia with an incidental finding of suspected right ventricular wall aneurysms in a dog.

A 3-year-old neutered male standard poodle mix dog was presented because of acute onset vomiting, increased respiratory effort, hyporexia, and progressive lethargy. On physical examination, intermittent tachycardia, tachypnea with mildly increased respiratory effort, and bilateral ventral muffled lung sounds were noted. Thoracic and abdominal computed tomography with contrast revealed a peritoneal pericardial diaphragmatic hernia (PPDH) with herniation of the liver and gallbladder, moderate abdominal lymphadenopathy, and mild pleural effusion. The dog underwent an emergency laparotomy and median sternotomy. Right ventral PPDH with a herniated, necrosed, and nonviable quadrate liver lobe and gallbladder; 2 suspected right ventricular (RV) aneurysms; and generalized mesenteric and portal lymphadenopathy were present. The affected liver lobe and gallbladder were removed; suspected aneurysms were managed by placing 2 purse-string sutures around the lesions and anchoring a pericardial flap over the aneurysms. The dog developed a ventricular arrhythmia postoperatively. Due to the arrhythmia and intraoperative findings of suspected aneurysms, echocardiography was performed and revealed focal RV systolic dysfunction, left ventricular systolic dysfunction, mild left ventricular dilation, and a hyperechoic area on the RV free wall, consistent with the purse string. An angiotensin-convertingenzyme (ACE) inhibitor was prescribed for left ventricular dilation. The dog was discharged 4 d postoperatively and was doing well 12 mo postoperatively. To our knowledge, this is the first report of a PPDH and suspected concurrent RV wall aneurysm in a dog successfully treated with a purse string and pericardial flap. Key clinical message: An RV aneurysm is extremely rare yet can be life-threatening in small animals. Early detection and treatment may minimize the risk of aneurysm rupture and sudden death.