ACUTE CNS SYNDROME OF BURROS 509 



III. /. .\i\.i(.l.i list Site liiiiid. ,1',) \v]>. Mii\i\'al time 24 holnl^. SaU'llitosis 

 (ari'ow) and iieuroiiopliagia. lerebruin. X 700. 



Neuronophagia and early satellitosis ( Fio-. 7 ) were observed in the head- 

 irradiated and Godiva animals, but were not distinct in the Nevada group. 



The portions of the central nervous system most se\erely in\olved were 

 the cerebral hemispheres, the cerebellum, and meninges, in that order. All 

 groups had a similar pattern. Vascular congestion and increase in size of 

 the perineuronal, periglial, and Virchow-Robin spaces were most prominent 

 in the head-irradiated animals. 



Lesions affecting the spinal cord, which in\olved both the parenchyma 

 and meninges, were infrequent and mild. These lesions were perivascular 

 cuflfing, hemorrhage, and congestion. 



Minor changes seen in the pituitary gland were infrecjuent peri\ascular 

 cuffing and hemorrhage in the pars ner\'osa. 



Lesions in other areas of the body were few and apparently of little 

 consequence, with the exception of the Godiva and some Nevada biaros, 

 in which there were multiple disseminated hemorrhages, pulmonarv edema, 

 and liver changes. 



Lymphadenitis and atrophy were noted in the lymph nodes of the head 

 and cerxical region in the head-irradiated animals. In the animals exposed 

 to total body radiation, there was generalized atrophy of all lymphoid tissue. 



Discussion 



There are many questions which must be answered before the significance 

 of the central nervous system syndrome in burros is fully realized. Why is the 



