PARALYSIS OF THE LOINS. 547 



groom coming into the stable the first thing in the morning, to be 

 more or less paralysed in his hind quarters. Or, having carried 

 his master in the early morning with all his wonted power and 

 dash, he may be discovered, similarly affected, after having been 

 left for a few hours in his stall, where, it is probable, he has 

 received a chill after work. In some cases, the attack is so severe 

 that the animal is unable to stand from the commencement, and 

 dies in a few days from exhaustion, brought on by excitement and 

 other nervous derangement. G-enerally speaking, as long as the 

 animal is able to keep on his legs, he shows but little signs of 

 constitutional disturbance. Sometimes, the attack is so mild, that 

 the horse continues capable of being ridden and driven, although 

 he will exhibit a certain loss of power in bearing weight, and, also, 

 in bringing his hind legs forward. 



The lameness from spinal congestion closely resembles that from 

 kumree (p. 543). 



If the animal does not die from the severity of the attack, the 

 disease will generally run a chronic course, and the horse may 

 slightly improve with time; may get comparatively well; or may 

 become gradually worse, and die after a few months. 



CAUSES. — There seems to be but little doubt that this paralysis 

 is caused by chill, and is due to congestion of the spinal cord, 

 on account of which there is an exudation of watery fluid from the 

 blood-vessels into the spinal canal, with consequent paralysis from 

 pressure on the cord. The all but universal idea in India is that 

 this paralysis is caused by the influence of cold winds ; hence, its 

 common designation, '"' a stroke of the wind." It is a well-estab- 

 lished fact that in places where spinal congestion is rife, cases are 

 especially liable to occur when a cold, dry, night wind springs up 

 after a sultry day. " Mr. Hallen, Inspecting Veterinary Surgeon 

 of the Bombay Army, has stated that in one instance he stopped 

 its recurrence in a native cavalry regiment, where it had been 

 prevalent, by building a wall high enough to shelter the horses 

 from wind" [Meyrick). The baneful effects of chill, particularly 

 in warm climates, are far greater when the air is laden with 

 moisture, than when it is comparatively dry; because, under the 

 former condition, evaporation from the skin is checked, sweat 

 bedews the body, and the superficial vessels are congested. If, 

 when in this state, the animal be exposed to a cold, dry wind, there 

 will be contraction of the blood-vessels of the surface of the body, 

 with a corresponding rush of blood to the underlying tissues, which 

 determination of blood may cause congestion of the vessels of the 

 spinal cord, with consequent paralysis. The effect of the direct 

 and powerful rays of the sun, probably, predisposes the cord 



35* 



