Video. Stage 1: Weaned pig with posterior weakness. In milder cases and in early stage of the disease, lesions are confined to the lumbar part of the spinal cord, resulting in posterior weakness with motor incoordination, pitching, and fibrillary muscle twitching. The consciousness is intact and the behavior and interest of this pig toward his environment is normal, just imitating the so-called rooting behavior. Stage 2: Weaned pig with serious tetraplegia. The cervical, dorsal, and lumbar parts of the spinal cord are equally affected, producing serious movement disorder of both the front and hind legs. The consciousness is intact. Stage 3: Weaned pig with end-stage encephalomyelitis. The brainstem and cerebellum are most likely affected, resulting in loss of consciousness, paresis, and serious flaccid paralysis of muscles. The animals retain their sensory functions and react to pain. (Source)