CHAPTEE LV. 



RABIES AND THE NEGRI BODIES (NEURORYCTES HYDROPHOBIA). 



RABIES, lyssa, hydrophobia, canine madness, "Wasserscheu," 

 "Tollwuth," "Hundswuth" (German), "rage" (French), is an acute 

 contagious, generally fatal disease of wolves, foxes, dogs, and more 

 rarely of other domestic animals and man. It is due to a specific 

 virus, which, with the infective saliva, gains entrance into the body of 

 a susceptible being through a wound generally caused by the bite 

 of some animal suffering from the disease. 



Historical and Occurrence. Rabies among dogs and the danger to 

 other animals from the bite of a rabid dog were known to Aristoteles, 

 the Greek naturalist and philosopher. That the saliva of such 

 animals was the carrier of the infective agent was shown experiment- 

 ally by Zinke, Gruner, and Salm in the early part of the last century. 

 Galtier, in 1879, was the first to inoculate rabbits, and in 1881 Pasteur 

 and his co-workers, Roux, Chamberland, and Thuilliers, became the 

 main exponents in the modern study of hydrophobia upon which is 

 based our exact knowledge of the disease and the methods of its 

 prevention by the inoculation of an attenuated virus. The disease has 

 been encountered almost all over the world, but has apparently been 

 kept out of Australia. It has been on the increase during the last 

 decade or two in the United States. 



Natural Infection. Natural infection, as a rule, is caused by the 

 bite of animals suffering from the disease, but sometimes dogs in the 

 early stages of unrecognized rabies have inoculated persons by licking 

 a place where there is a small abrasion of the skin. The saliva is 

 most infective after the disease has well developed and during its 

 subsequent course, but may also be infective before any symptoms 

 of rabies appear. The danger of the bite from a rabid animal depends 

 upon the greater or lesser virulency of the saliva, upon the extent of the 

 wound, the amount of laceration, the vascularity and nerve supply 

 of the tissue, and upon the greater or lesser distance of the wound 

 from the central nervous system. The less the distance the greater 

 the danger; hence, wounds of the face or head are particularly dan- 

 gerous. Horses and cattle are especially liable to contract hydro- 

 phobia if bitten by rabid dogs, wolves, or foxes in the lips, cheeks, or 

 nose. The danger of the bite is much lessened if the parts are covered 

 by a dense fur, or, in the case of man, by heavy clothing. It has 

 been shown that shorn sheep are much more liable to develop rabies 

 after being bitten than those covered with a dense wool. The virus, 



