PARALYSIS. 209 



]:)riinary affection. Tn the majority of cases, however, hemiplegia 

 arises from emboli obstructing one or more blood vessels of the brain, 

 or the rupture of some vessel the wall of which had become weakened 

 by degeneration and the extravasation of blood. Sensibility in most 

 cases is not impaired, but in some there is a loss of sensibility as well 

 as of motion. In some cases the bladder and rectum are involved in 

 the paralysis. 



.Symptoms. — In hemiplegia the attack may be very sudden, and the 

 animal fall down powerless to move one side of the body, one side of 

 the lips will be relaxed; the tongue may hang out on one side of the 

 mouth; the tail curved around sideways; an inability to swallow food 

 or water nuiy be present, and often the urine dribbles away as fast as 

 it collects in the bladder. Sensibility of the affected side may be 

 entirely lost or only partial; the limbs may be cold and sometimes 

 unnaturally warm. In cases wherein the attack is not so severe the 

 animal may be able to maintain the standing position, but will have 

 great difficulty in moving the affected side. In such cases the animal 

 may recover from the disability. In the more severe, where there is 

 complete loss of power of movement, recoveries are rare. 



Paraplegia, or transverse paralysis of the hind extremities. — Pa- 

 ralysis of the hind extremities is usually due to some injury or inflam- 

 mation affecting the spinal cord. (See '' Spinal meningitis,'' p. 211, 

 and ''Myelitis, p. 213.) It may also be due to a reflex irrigation 

 from disease of peripheral nerves, to spinal irritation or congestion 

 caused by blood poisons, etc. 



Symptoms. — When due to mechanical injury of the spinal cord, 

 from a broken back or spinal hemorrhage, it is generally progressive 

 in its character, although it may be sudden. When it is caused by 

 agents in the blood, it mav be intermittent or recurrent. 



Paraplegia is not difficult to recognize, for it is characterized by a 

 weakness and imperfect control of the hind legs and powerless tail. 

 The urine usually dribbles away as it is formed and the manure is 

 pushed out, ball by ball, without any voluntary effort, or the passages 

 may cease entirely. When paraplegia is complete, large and ill- 

 conditioned sores soon form on the hips and thighs from chafing and 

 bruising, which have a tendency to quickly Aveaken the animal and 

 necessitate his destruction. 



Locomotor ataxia., or incoordination of movement. — This is charac- 

 terized by an inability to control ])roperly the movement of the limbs. 

 The animal appears usually perfectly healthy, but Avhen he is led out 

 of his stall his legs have a wobbly movement, and he will stumble or 

 stagger, especially in turning. When this is confined to the hind 

 parts it may be termed a modified form of paraplegia, but often it 

 may be seen to affect nearly all the voluntary nniscles when they are 

 H. Doc. 795, 51V2 14 



