Acute pelvic limb paralysis occurred in a racing Greyhound after a traumatic incident. During myelography, a dorsal laceration of the dura mater was detected at T12–13. Immediate hemilaminectomy was performed at T12–13, but neurologic status did not improve. At necropsy there was epidural and subdural hemorrhage at the T12–13interspace, and malacia and swelling of the spinal cord at that level. Intramedullary hemorrhage, malacia, and free fibrocartilaginous material characterized histopathology of the lesion. Possible mechanisms of the traumatic disk extrusion are disc