Neuropathologic changes in 15 horses with naturally occurring Venezuelan equine encephalomyelitis
Roberts, E.D.; Sanmartin, C.; Payán, J.; Mackenzie, R.B.
American Journal of Veterinary Research 31(7): 1223-1229
1970
ISSN/ISBN: 0002-9645 PMID: 5447695 Document Number: 26751
Brain material from 15 horses which had died of encephalitis during outbreaks of VEE in Colombia was examined histologically. The virus was isolated from seven of the horses. In every case there was a perivascular inflammatory reaction in the cerebral cortex. Both astrocytes and neutrophils were found in the perineuronal spaces of the cerebral cortex. In the midbrain area, the vascular reaction was less intense, and there were more lymphocytes and macrophages. Thrombosis and necrosis of the smaller arteries often occurred. In the medulla and cerebellum, focal glial nodules, satellitosis, and predominantly lymphocytic perivascular reaction were seen. Glial nodules were occasionally seen in the ventral gray horn of the spinal cord. The inflammatory changes were similar to those reported in naturally occurring eastern equine encephalomyelitis.