Rear limb paralysis in market age swine occurs sporadically and can be attributed to a variety of causes, including fractures, spinal abscesses, and ischemic myelomalacia due to cartilage (fibrocartilage) emboli from the nucleus pulposus.11,16 Cartilage emboli resulting in ischemic myelomalacia have been reported in several species, most commonly in adult largeand giant-breed dogs and rarely in swine.4– 6,9,10,14–16 In a recent report, there was a high incidence of rear limb paresis/paralysis in a large group of finishing pigs caused by ischemic myelomalacia due to fibrocartilage emboli in the spinal cord.3 However, no factors were identified in the affected pigs that predisposed them to development of cartilage emboli. In this follow-up report to that case, we describe an additional group of finishing pigs with ischemic myelomalacia caused by cartilage emboli. These pigs also had chronic diskospondylitis. Market weight swine in a production unit with approximately 1,800 grow–finish swine developed a high incidence of acute rear limb paralysis following transportation to market (25/1,800 swine affected).3 These swine were from a high-lean, heavily muscled genetic line that had a rapid growth rate, and they were extremely large (127 kg) when transported. Nine of these paralyzed swine were submitted to the Iowa State University Veterinary Diagnostic Laboratory (ISU-VDL) for necropsy. All 9 of these swine had ischemic myelomalacia associated with cartilage emboli in spinal cord vessels. However, abnormalities in the spine were not detected, and a predisposing cause for the cartilage emboli was not discovered. Several weeks later, acute rear limb paralysis developed in several market weight swine in additional groups (500 swine/group) from the same production unit. The circumstances of this episode were similar to those of the previous episode of paralysis, occurring after transportation to market. Five paralyzed swine were submitted to the ISU-VDL for necropsy and complete examination of the spinal cord and spine. The spinal cords were removed following dorsal laminectomy, and the spines were sectioned longitudinally with a bandsaw in a dorsoventral vertical plane. Sections of vertebrae, intervertebral disks, and the entire spinal cords from all 5 pigs were fixed in 10% neutral buffered formalin. Vertebrae were demineralized in a 25% aqueous solution of formic acid, and all tissues were embedded in paraffin, sectioned at 5 mm, and stained with hematoxylin and eosin. Replicate sections were stained with Alcian blue at pH 2.5 to identify fragments of nucleus pulposus.