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

This is the first reported case of both bilateral renal arterial malformations and bilateral spontaneous subcapsular and perirenal hemorrhage in the absence of neoplasia, coagulopathy, or trauma in a dog. Advanced imaging modalities, including selective angiography, were required to diagnose this condition successfully. Arterial malformations should be considered as a differential diagnosis in cases of hemoretroperitoneum. Nephrectomy due to perirenal hemorrhage should be cautiously considered, especially in the absence of angiography, because of the sequential bilateral nature of this case. Conservative management in this case resulted in a good long-term outcome 10 months later.