Arterial malformations leading to bilateral spontaneous renal hemorrhage in a dog.

Objective: To describe the clinical presentation, diagnostic imaging, management and follow up of a dog that presented with sequential, bilateral, spontaneous subcapsular and perirenal hemorrhage (Wunderlich Syndrome) due to bilateral renal arterial malformations.
Case Summary: A 9-year-old male intact Field Spaniel presented for acute onset abdominal pain following a possible syncopal episode. Abdominal ultrasonography, contrast enhanced ultrasound and computed tomography (CT) revealed right sided perirenal hemorrhage, which extended into the peritoneum. The dog was discharged following stabilization with analgesia, fluid therapy, and tranexamic acid. One month later, the patient presented with identical clinical signs. A CT scan at this stage revealed bilateral renal infarcts with new left sided perirenal hemorrhage. Abdominal ultrasound and contrast enhanced ultrasound were repeated and showed similar findings. Follow up with four-dimensional-CT angiography revealed bilateral renal arterial malformations, likely causing spontaneous renal hemorrhage and secondary subcapsular hematomas, retroperitoneal and peritoneal hemorrhage.