Focal symmetrical encephalomalacia in a 6-month-old Dorset sheep

Neurological examination of a sheep that had acute onset of recumbency and mental depression indicated a diffuse symmetrical thalamocortical lesion. Cerebrospinal fluid analysis suggested a degenerative central nervous system disease. Thiamin administration resulted in partial and temporary improvement. Brain histological lesions were typical of focal symmetrical encephalomalacia.