124 DISEASES OF CATTLE. 



displacement of the bones (vertebrae) which form the spinal column, 

 by compressing the spinal cord produces paralysis, which varies in its 

 effect according to the part of the cord that is compressed. If the 

 fracture is above the middle of the neck death soon follows, as commu- 

 nication between the brain and diaphragm the essential muscle of 

 inspiration is stopped. The phrenic nerve, which supplies the dia- 

 phragm with motor impulse, is formed by the union of spinal nerves 

 below the middle of the neck, and when the cord is compressed between 

 the origin of this nerve and the brain the diaphragm is paralyzed and 

 death must result. When the fracture is farther down in the neck, 

 posterior to the origin of the phrenic nerve, the breathing continues, 

 but there is paralysis in all parts posterior to the fracture, including the 

 fore and hind legs. Whenthe fracture is in the region of the loins the 

 hind legs are paralyzed, but the fore legs are not. If the fracture is in 

 the sacrum (the division of the spinal column between the loins and the 

 tail) the tail alone is paralyzed. 



As a matter of course, when the back is broken there is no remedy ; 

 the animal should be bled to death and converted into meat at once. 

 The animal not being able to rise after the accident, together with the 

 fact that sensation is lost, as evidenced by sticking a pin into the para- 

 lyzed parts, should decide the question. 



PARALYSIS. 



Paralysis, or loss of motion in a part, may be due to a lesion of the 

 brain, of the spinal cord, or of a nerve. It may also be caused by reflex 

 irritation. When the paralysis affects both sides of the body, posterior 

 to a point, it is further designated by the technical name of paraplegia. 

 When one side of the body (a lateral half) is paralyzed, the technical 

 term liemiplegia is applied to the affection. When paralysis is caused 

 by a lesion of a nerve, the paralysis is confined to the particular part 

 supplied by the affected nerve. 



As already pointed out, paralysis may be due to concussion of the 

 spine; fracture of a bone of the spinal column with consequent com- 

 pression of the spinal cord; concussion of the brain; compression of the 

 brain. An injury to one side of the brain may produce paralysis of 

 the same side of the head, and of the opposite side of the body hemi- 

 pleyia. Paralysis may occur in connection with parturient apoplexy, 

 lead poisoning, ergotism, etc. 



Paraplegia, like other diseases, has been traced to moldy food. In one 

 outbreak on record, complete paralysis of the posterior parts of the 

 bodies of seven oxen was attributed to this cause. Reflex paraplegia, 

 associated with indigestion and impaction of the rumen, is recognized 

 by practitioners. This is usually a mild form, and generally passes 

 away in a few days, especially when the cause indigestion, impactiou 

 of the rumen responds to proper treatment. Cows heavy with calf 

 are sometimes affected with a form of paraplegia, which usually at- 



