PEACTICE OF MEDICINE AND HYGIENE 



dog by fleas which are nourished by the blood 

 of the dog and from which hardly any dog is 

 free. It has been shown conclusively that this 

 companion of the dog can convey anthrax and 

 plague. Virchow insisted that rabies is an 

 infectious disease. It remained for Pasteur to 

 carry out studies which have conclusively 

 proved its infectious character. His investiga- 

 tions have been continued by Roux, Negri and 

 a large number of other biological students. 



The disease causes the development in the 

 nerve centers of certain structures called Negri 

 bodies. The discovery of these confirms the 

 diagnosis. Otherwise diagnosis must be made 

 positive by inoculation. However, no anatom- 

 ic finding is more characteristic than the 

 symptoms manifested. Study of these animals 

 shows that the dog to be feared is the one that 

 has a listless expression, with altered voice and 

 hanging jaw and tongue; he wanders about 

 aimlessly, is restless, bites at imaginary objects, 

 or sulks into a corner; often he display an 

 unusual disposition to lick his master's hand 

 or face. The disease seems often to spring up 

 sporadically because infected dogs are prone 

 to wander off, travelling often twenty or 

 forty miles, and then dying in some corner, 



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