Polioencephalomalacia in the dog.

Disturbance of cerebral blood flow from causes such as meningitis, thromboembolic disease and atherosclerosis was considered an important factor in the pathogenesis of polioencephalomalacia in 25 dogs. In dogs with polioencephalomalacia of undetermined cause, the distribution of lesions in neocortex and paleocortex suggested a change of neuronal metabolism secondary to cerebral anoxia/ischemia. Five dogs with canine distemper infection had bilateral necrosis of the hippocampus and pyriform cortex. Convulsions, central visual impairment and hemiparesis were the most prominent neurologic signs.