410 DISEASES OF CATTI^. 



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 several centuries prior to the beginning of the Christian 

 era, and from the earliest dawn of history the disease has been feared 

 and dreaded. Its temble manifastations have always been sur- 

 rounded with an atmosphere of awe and mystery, and it is not sur- 

 prising 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 concern- 

 ing rabies have been comparatively recent, and have appeared for 

 the most part in scientific periodicals, fallacies in regard to the dis- 

 ease continue to have a strong hold upon the public mind. For in- 

 stance, 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 indisputable. 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 contagion can be propagated only in the 

 body of an animal. It is transmitted naturally from one animal to 

 another solely by bites, and the old idea of spontaneous appearance of 

 the disease is absolutely fallacious. It may be produced artificially 

 by inoculating susceptible 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, un- 

 der natural conditions, is introduced 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 sec- 

 tions of the United States. 



