Traumatic pericardial rupture with secondary cardiac herniation in a dog.

Objective: To describe the unique finding and treatment of a dog with cardiac herniation due to traumatic pericardial rupture.

Case Summary: A 6.5-year-old entire male Yorkshire Terrier was presented for further management after being hit by a car. Despite suspected significant intrathoracic trauma at that time, the patient regained hemodynamic stability and had orthopedic surgery to correct a right iliac fracture. The patient was readmitted to the hospital 12 days following the initial visit due to considerable respiratory difficulty after accidentally being dropped several feet. Thoracic radiographs revealed an unusual severe mediastinal shift to the left with an atypical position of the cardiac silhouette against the left lateral thoracic wall. Due to the severe respiratory compromise of the patient and newly developed pneumothorax, an exploratory thoracotomy was recommended, where a complete rupture of the pericardium was identified, with secondary left-sided prolapse of the heart. Other more common intrathoracic injuries (ie, lung perforation, rib fractures) were also identified and partially repaired. The patient recovered successfully and was discharged 4 days postoperatively.

New Or Unique Information Provided: This is the first case report in the veterinary literature of traumatic pericardial rupture and cardiac herniation. According to human case descriptions, this is a rare and often fatal occurrence, which can be significantly challenging to diagnose preoperatively or antemortem. Emergency veterinary clinicians should be aware of this rare but important complication of blunt thoracic trauma. Surgical intervention may be necessary in cases with suspected or confirmed entrapment of great vessels or cardiac chambers, although these abnormalities were not present in this case.