394 ' DISEASES OF CATTLE. 



RABIES OF CATTLE. 



Rabies is a disease preeminently affecting the canine race, although 

 all warm-blooded animals, including man, are susceptible to the mal- 

 ady, which is always communicated through bites from a preceding 

 case. It has required many years of patient scientific research to lead 

 the ablest investigators to a clear comprehension of the cause, nature, 

 and characteristics of this affection. It was known and described sev- 

 eral centuries prior to the beginning of the Christian era, and from 

 the earliest dawn of history the disease has been feared and dreaded. 

 Its terrible manifestations have always been surrounded with an 

 atmosphere of awe and mystery, and it is not surprising that myths, 

 fallacies, and misconceptions in regard to it have been common and 

 widely accepted. As the investigations by which we have come to a 

 tolerably clear understanding of the facts concerning rabies have 

 been comparatively recent and have appeared for the most part in 

 scientific periodicals, fallacies in regard to the disease continue to 

 have a strong hold upon the public mind. For instance, it is still a 

 widely prevalent belief that if persons or animals are bitten by a dog 

 they are liable to become rabid if the dog should contract the disease 

 at any future time. There is no foundation for this impression, and 

 it would be a great comfort to many people who are now and then 

 bitten by animals if the fallacy of this idea were appreciated. All 

 experience, both scientific and practical, goes to show that rabies is 

 transmitted only by animals that are actually diseased at the time 

 the bite is inflicted. Rabies is an infectious disease involving the 

 nervous system and characterized by extreme excitability and other 

 nervous disorders and always terminating in death. The contagion of 

 this disease has never been isolated, but the fact that it is caused by 

 a specific organism principally found in the nervous system is indis- 

 putable. For instance, if an emulsion of the brain of a rabid animal 

 is filtered through a germ-proof filter, the filtrate will be harmless. 

 This fact indicates that the infectious principle is not in solution, but 

 is an organism withheld from the filtrate by the filter. This conta- 

 gion can only be propagated in the body of an animal. It is trans- 

 mitted naturally from one animal to another solely by bites, and the 

 old idea of spontaneous appearance of the disease is absolutely falla- 

 cious. It may be produced artificially by inoculating .-usceptible 

 animals with an emulsion of the brain or spinal cord , % as well as the 

 saliva, milk, and other secretions of the affected animal. The blood, 

 on the contrary, seems to be free from the infectious principle. The 

 saliva contains the virus, which, under natural conditions, is intro- 

 duced into or under the skin on the tooth of the rabid animal. The 

 disease is widespread, being found in many countries of Europe, 

 Asia, and Africa and in certain sections of the United States. 



Owing to the rigid quarantine regulations enforced against dogs 

 imported into Australia, that country remains absolutely free from the 



