DISEASES OF THE SPINAL CORD. 305 



its membraaes are simultaneously involved, and where the 

 affection is mainly confined to one, it is often difiicult to 

 diasrnose which of these structures is the chief seat of in- 



o 



flammation. 



Etiology. — Spinal inflammation may be acute or chronic. 

 Acute spinal inflammation may be due to injury, such as 

 fracture or displacement of the vertebral segments resulting 

 in compression of the cord. 



When arising idiopathically, it is often very difficult to 

 trace the cause, but hereditary predisposition is certainly in 

 many instances traceable. 



Exposure to cold and damp, especially after a heavy 

 day's work, are potent causes of inflammation of the spinal 

 cord, and of its membranes. 



Symptoms. — Premonitory symptoms are more likely to 

 be manifested when the membranes are the special seat of 

 inflammation, whereas they are more likely to be absent 

 when the inflammation is especially concentrated in the cord 

 itself. 



Before paralysis comes on, in cases of inflammation of 

 membranes especially, spasmodic contractions of the large 

 muscles connected with the trunk and limbs, chiefly the 

 hind ones, are observed. 



Febrile symptoms are manifested, and perspiration be- 

 dews the body. The legs are lifted up and placed upon the 

 ground in quick succession. The animal suffers great pain, 

 and is very restless and excitable, and is disturbed by the 

 slightest movements of the attendants. 



Now and again he may have intervals of calm and quiet, 

 and cessation from spasms. 



But after the lapse of eight to twelve hours or so, from 

 the pain caused by progress of the inflammatory action, 

 and from the exhaustion, the animal falls prostrate to the 

 ground. 



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