Aortic injection study in a dog with significant aortic regurgitation (arrow) and a small ductus diverticulum (DD). The right coronary artery (RCA) originates from the ventromedial sinus of Valsalva. The paraconal (Pc) artery courses over the ventricular septum. Dogs typically have a dominant left coronary artery distribution since the subsinuosal (Ss) artery is a branch of the circumflex (LCx) artery.