SECTION VII 

 THE NERVOUS SYSTEM 



DISEASES of the nervous system of the various 

 domesticated animals have not been sufficiently 

 investigated for a good description to be given 

 of them. This is particularly true in regard to diseases 

 of the nervous system in swine. 



Malformations of the brain or spinal cord are com- 

 mon in swine. They are observed principally by the 

 breeder and in small pigs, as the majority of these mal- 

 formations are of such a nature that the affected animal 

 dies soon after birth. Cranial and spinal clefts, with 

 associated hernia of the meninges, brain, or spinal cord, 

 are the most common deformities. 



Functional disturbances of the brain, such as delirium, 

 are sometimes observed, but this condition is not com- 

 mon. It is usually the result of organic disease of the 

 brain, although it may be caused by intestinal parasites. 

 The affected swine champ their jaws, grunt, run against 

 the fence, posts, or similar objects, tremble, and may even 

 bite. When the cause is removed the animals make a 

 speedy recovery, although succeeding attacks may occur. 



Viciousness is closely associated with delirium. This 

 condition is dependent upon the nature and tempera- 

 ment of the animal and is manifested by a desire to attack 

 man or other animals. Vicious swine bite, and boars use 

 their tusks to inflict injuries, and are sometimes successful 

 in disemboweling their victim. Viciousness is inherited 

 or acquired, and vicious swine should never be used for 

 breeding purposes. Viciousness is acquired by swine 

 that are nervous. Such swine soon become irritable, 

 then vicious, as a result of teasing or brutal treatment. 

 One instance is recalled of a nervous sow that became 

 vicious because the owner's son irritated and tantalized 



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