286 MANUAL OF EQUINE MEDICINE. 



numbness, burning, cutting, constriction, and various other 

 kinds of pain. The agony of enteritis, and several other 

 diseases of the bowel and other organs, are especially acute 

 in the horse. 



By anaesthesia is meant impairment or loss of sensation. 

 Hypersesthesia and anaesthesia are usually met with together, 

 associated with motor paralysis. 



COMA AND INSENSIBILITY. 



Under this heading we do not purpose to discuss the affec- 

 tion spoken of as ' sleepy staggers,' sometimes termed ' coma,' 

 but to consider coma in its more general and extended sense. 



Coma is a progressive loss of function, which begins at 

 the cerebrum, and is characterized at the outset by loss of 

 consciousness, perception, and voluntary movement. 



Automatic and reflex movements continue at first ; but 

 when the large ganglia at the base of the brain become 

 involved, the capacity for automatic movement becomes 

 more and more limited. 



In fatal cases, the loss of function progresses, and gra- 

 dually extends to the medulla, which is the seat of the 

 respiratory, circulatory, and other centres. 



Death then soon ensues. 



The causes of coma are intense congestion or anaemia of 

 the brain, altered conditions of the blood, and injury or 

 compression of the brain. 



STAGGERS. 



To several affections of the horse the term 'staggers' has 

 been applied at various times by different authors. 



Indeed, there are at least as many as five distinct affec- 

 tions which have received this name, and there are many 

 more of which * staggers' is a feature. 



Staggers may be due to ^primary disease of the nerve-centres, 

 or to influences affecting them from disease of other organs. 



