Poonacha K B, Gregory C R, Vickers M L
Vet Pathol. 1998 Nov;35(6):535-8. doi: 10.1177/030098589803500608.
The primary lesions of eastern equine encephalomyelitis (EEE) virus infection in the horse are limited to the brain and spinal cord. Intestinal lesions in addition to the changes in the central nervous system were found in a 6-month-old male Tennessee Walking Horse. One week prior to death, this colt was vaccinated for EEE virus, western equine encephalomyelitis virus, influenza virus, equine rhinopneumonitis virus, and tetanus. The clinical signs consisted of ataxia and rear-end weakness, with a body temperature of 102.8 F. Gross lesions consisted of yellowish discoloration, swelling, edema, and hemorrhage of the brain stem and dark discoloration of the gray matter of the spinal cord. Microscopic lesions in the small intestine were mainly in the muscular layer and consisted of multifocal areas of myonecrosis and lymphomonocytic infiltration with a few focal areas of mild fibrous connective tissue proliferation. Occasional focal mild perivascular lymphocytic infiltration was observed in the submucosa. Lesions in the brain and spinal cord consisted of widespread areas of perivascular lymphomonocytic cuffing, focal areas of necrosis, neutrophilic infiltration, hemorrhage, neuronal degeneration, and gliosis. Hepatic changes consisted of periportal lymphocytic infiltration and mild vacuolar degeneration of hepatocytes. EEE virus was isolated from the intestine and detected by DNA in situ hybridization.
马东部马脑脊髓炎（EEE）病毒感染的主要病变局限于脑和脊髓。在一匹6个月大的雄性田纳西走马中，除了中枢神经系统的变化外，还发现了肠道病变。这匹小马在死亡前一周接种了EEE病毒、西部马脑脊髓炎病毒、流感病毒、马鼻肺炎病毒和破伤风疫苗。临床症状包括共济失调和后肢无力，体温为102.8华氏度。大体病变包括脑干发黄、肿胀、水肿和出血，以及脊髓灰质颜色变深。小肠的微观病变主要在肌层，表现为多灶性肌坏死和淋巴细胞单核细胞浸润，伴有少数局灶性轻度纤维结缔组织增生。在黏膜下层偶尔可见局灶性轻度血管周围淋巴细胞浸润。脑和脊髓的病变包括广泛的血管周围淋巴细胞单核细胞套袖状浸润、局灶性坏死、中性粒细胞浸润、出血、神经元变性和胶质细胞增生。肝脏变化包括门周淋巴细胞浸润和肝细胞轻度空泡变性。从肠道中分离出EEE病毒，并通过DNA原位杂交检测到。
