58 DISEASES OF SWINE 



ushered in by a period of dulness, but in most cases 

 the hog appears excited from the first. During the 

 period of excitement or delirium ' it champs its 

 teeth, froths at the mouth, walks or runs about the 

 pen, generally in a circle and without showing much 

 ability to dodge objects coming its way. It squeals 

 and grunts, tries to climb up the sides of the pen, 

 presses its head against the wall or fence, and finally 

 falls over in a convulsion. In a short time it may regairi 

 its feet, or continue lying on the ground in a stupor, 

 which finally ends in death. In heat-stroke sudden 

 collapse, staggering gait, convulsions, and uncon- 

 sciousness are the usual symptoms. 



In moderate congestion of the brain, the duration 

 of the disease is short and a complete recovery may 

 occur. When the congestion is severe, it usually 

 terminates in an inflammation of the brain, sometimes 

 death. The outcome of the latter disease is un- 

 favorable, and in most cases runs a short course. 



Lesions. — The coverings of the brain are con- 

 gested and inflamed, appearing thickened and red- 

 dened. If the inflammation is caused by a blow on 

 the head, the skin and other tissues in the region 

 of the injury show the effect of the blow, and the 

 coverings are especially apt to show marked local 

 lesions. 



A portion of the gray matter of the brain, depend- 

 ing on the extenj: of the inflammation, is darker 

 colored than normal and stained with blood. Small 

 red areas may be seen scattered through the nerve 

 tissue, and the whole structure is more or less soft- 



