472 RABIES 



comes on with restlessness, depression, a tendency to lick 

 objects and paralysis of the muscles which close the jaws. As 

 a consequence of the paralysis, the lower jaw drops, the 

 animal is unable to close the mouth, the tongue hangs out and 

 an abundance of saliva escapes. The mucous membrane of 

 the mouth becomes dry, discolored and covered with dust. 

 The animal remains quiet, it does not respond to calls and 

 appears to understand its helplessness. Bouley states that the 

 animal cannot bite and does not desire to bite. When dumb 

 rabies follows the furious form, the desire and tendency to bite 

 may be retained even after the jaw is paralyzed. 



The course of the disease is short, death usually occurring 

 in from two to four days. 



§ 373. Morbid anatomy. One of the striking charac- 

 teristics of rabies is the absence of constant, recognizable 

 lesions. The mucosa of the pharynx and larynx are con- 

 gested. The spleen is sometimes enlarged and dark colored. 

 In dogs the stomach often contains a variety of foreign matter 

 such as earth, stones, pieces of iron, bits of leather, wood, etc. 

 Axe reports finding such foreign substances present in 90 per 

 cent, of 200 cases he examined. Galtier reports such findings 

 in from 50 to 70 per cent. In experimental animals and cattle 

 the writer has rarely found them. It seems to be true that 

 the obvious lesions are not constant and it is probable that 

 the pronounced changes occasionally found in a single organ 

 are accidental or secondary rather than primarily related to 

 the disease. The lesions in the brain and spinal cord are 

 likewise variable. In some cases there is a marked hyperemia, 

 -while in others the brain appears to be normal. 



Certain investigators, however, have found histological 

 changes which to their minds have been pathognomonic of the 

 disease. The close simulation of the nervous lesions to those 

 due to other diseases, and the possibility of greater or less 

 post-mortem changes will foster an element of doubt in the 

 minds of the majority of working histologists. This doubt in- 

 stead of diminishing shows a tendency to grow when a review 



Digitized by Microsoft® 



