Peritoneal-pericardial diaphragmatic hernia (PPDH) is a congenital communication remaining between the pericardial and peritoneal spaces, through the diaphragm. These hernias can be of variable size and frequently contain the liver, but less commonly the small intestine, spleen and stomach. This is a very rare condition in dogs. Other congenital defects may be present (umbilical hernia, sternal deformity or ventricular septal defect).

Clinical signs
Frequently PPDH is found as an incidental finding and most patients are asymptomatic.
Clinical signs include a muffled heart sounds on physical exam.
Associated defects may be detected such as umbilical hernia, sternal deformity or ventricular septal defect. Occasionally gastrointestinal sounds can be auscultated over heart. "Empty" abdomen may be appreciable on abdominal palpation. Symptoms such as dyspnea, intermittent diarrhea or regurgitation can also be seen

Diagnosis is usually made incidentally on radiographic, ultrasonographic or CT imaging studies.

Treatment and Prognosis:
Prognosis is good following surgical correction.
Good prognosis is seen in asymptomatic patients, but may develop signs in the future.
Surgical correction is indicated if the patient is symptomatic.

Case of the month:
Patient is a 6 year old female spayed domestic shorthair that presented for routine nail trim. The technician noticed some wheezing when removing patient from her carrier. O reported p had been otherwise okay at home. Physical exam was within normal limits. Blood work was unremarkable. Radiographs revealed severe cardiomegaly (see images below). The patient was referred to the cardiologist for echocardiogram which revealed the liver adjacent to the heart consistent with Peritoneal-pericardial diaphragmatic hernia. The radiographic appearance of the enlarged heart was primarily a result of a diaphragmatic hernia with the liver overlying the cardiac silhouette. There was no evidence of vital organ entrapment such as GI tract or spleen. It is suspected that clinical signs were not related to PPHD complications and those symptoms were likely a result of another condition. No specific therapy was indicated at that time. Patient was discharged with specific instruction to monitor at home and recheck if no change in clinical signs. Patient has been doing well home with no further problems.