DISEASES OP THE NERVOUS SYSTEM. 



EXAMINATION OP THE NERVOUS SYSTEM. 



Disturbances of the nervous system are marked by impair- 

 ment of consciousness, sensitiveness, and motility. Besides these 

 there are eomplicatioas in the functions of the eyes, ears, and the 

 digestive system. 



1. The Disturbances of Consciousness are variously defined 

 according to their intensity. Dulness (indifference to any exter- 

 nal influeaces), somaoleocc (drowsiaess, sleepiness, the patient 

 may be awakened easily), stupor (deep sleep, difficult to arouse 

 the patient), coma (entire uQconsciousuess, the animal is not dis- 

 turbed by external influences). In extreme cases of unconscious- 

 ness all sphincters of the body become relapsed. Such cases are 

 found in the various diseases of the brain and its coverings and 

 in cases of injury and concussions of the brain ; it is also seen in 

 poisoning by narcotics, in uraemia, in acute auseraia, and in all 

 diseases accompanied by intense fever and pain. Short attacks 

 of unconsciousness may occur in the form of dizziness, and are 

 seen occasionally as the result of great excitement or pain (in oper- 

 ations); and also idiotism, which occurs in rare instances as a 

 result of distemper, when it assumes the nervous form. 



2. Disturbance of Sensitiveness. This is not easily recog- 

 nized in the dog. In all instances i| is advisable to cover the 

 patient's eyes, and compare the sensitiveness of the affected side 

 with that of the healthy one. In cases of hsemaphraic diseases 

 we test the sensitiveness of the skin by pricking it slightly with 

 a needle or letting cold water drop upon it so as to produce some 

 irritation or symptom of pain. A test may also be made by 

 means of a battery; still this method has failed to be as reliable 

 and practical as the needle and cold-water test have been to the 

 author. 



Total ancesthesia occurs, as a rule, from poisoning, and must not 



be mistaken for a want of reaction when in a comatose condition. 



Local anaesthesia — that is to say, a more or less circumscribed or 



disturbed zone of sensibility — may be found in any part of the 



( 196 ) 



