Proximal aortic dissection (dissecting aortic aneurysm) in a mature ostrich

The gross and histopathologic lesions observed in a case of spontaneous pro ximal aortic dissection (dissecting aortic aneurysm) in a mature ostrich ar e reported. At necropsy, a dissecting intramural hematoma was seen in the p roximal aorta, extended about 12 cm distally from the aortic valves. Histop athologic changes in aortic dissection included fragmentation and disruptio n of elastic laminae, presence of cystic extracellular spaces, and pooling of ground substance in the tunica media. Hepatic copper levers were measure d, and the low concentration found suggested that a copper deficiency toget her with other risk factors such as the elevation of blood pressure may hav e been implicated in the development of the aortic dissection seen in this ostrich.