XXXIX. 

 CONTAGIOUS DISEASES OF CATTLE. 



CATTLE PLAGUE. 



This disease, known also as Rinderpest, is a specific, malig- 

 nant, and contagious fever, prevailing particularly in the Asiatic 

 countries. It is not known in America. If found in this coun- 

 try at all, it arises from direct or indirect communication with 

 imported cattle. The period of incubation varies from four to 

 eight days, at the end of which time the local manifestations are 

 developed. Like all fevers, it runs a definite course. It usually 

 terminates fatally; but where recovery takes place, the animal is 

 rendered unsusceptible to another attack. It is peculiar to the 

 bovine family, but has been communicated to sheep, goat, deer, 

 camel, giraffe, antelope, and gazelle. 



The disease is induced by a streptococcus, which causes a 

 morbid state of the blood. Serum obtained from the blood of 

 affected animals may produce the disease in another animal by 

 inoculation. The morbid poison is also contained in the dis- 

 charge from the mouth, eyes, and intestinal canal. If a small 

 portion of this be placed in the blood of a healthy animal, the 

 whole mass of blood will become infected in forty-eight hours, 

 and if a small portion of this newly inoculated blood be inocu- 

 lated in still another animal, it will transmit enough poison to 

 give the disease to the other animal. The morbid poison may be 

 diffused and the disease communicated by the air for a distance 

 of about five hundred yards; but it is said that beyond this dis- 

 tance the poison is inoperative. It is also conveyed by flies, 

 which, after rising from a sick animal or its offal, alight on 

 healthy animals. Many theories have been advanced as to the 

 true nature of the plague and its identity with various human 



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