INFECTIOUS DISEASES OF CATTLE. 393 



appeared spontaneously under the influence of deteriorated food and 

 long and -exhausting drives, also during unusual meteorological con- 

 ditions. This view, however, is no longer maintained. It is probable 

 that the disease in its home in Asia is perpetuated by continual infec- 

 tion of fresh animals, and some authorities even go so far as to l^elieve 

 that the disease would be entirely stamped out, even in its native 

 haunts, by a destruction of all sick and infected herds. However this 

 may be, the success of such an undertaking would largely depend on 

 the nature of the cause. If a strictly parasitic organism, like the con- 

 tagion of pleuropneumonia, it might be couipletely extirpated in this 

 way. If, how^ever, the germs or bacteria may live and multiply out- 

 .side of the bovine body, in the soil, water, or in some other animal, 

 extirpation would be im])ossible. 



The virus may be transmitted from sick to healthy animals in a 

 variety of ways, both direct and indirect. It is said to be present 

 in the various excreta of the diseased, such as the discharges from 

 the nose, and the saliva, the urine, and the manure. It retains its 

 vitality outside of the body in a moist state for months, and the 

 disease is reported to have developed after feeding hay a year after 

 it had lain in an infected stable. Hence manure and the fodder and 

 bedding soiled with discharges may convey the disease. Persons 

 may carrv^ the virus on their shoes, clothing, and implements. Even 

 small animals, such as cats and rats, which frequent bams and stables 

 have been looked upon as carriers of the vims. 



Cattle are very susceptible to the disease, and in its virulent type 

 all those exposed are said to become infected. Buffaloes, sheep, and 

 goats are likewise susceptible, but in a less degree. 



It is also claimed that animals after having passed through one 

 attack are able to resist successfully future attacks. Inoculation 

 with virus is said to produce immunity, but the process of inocula- 

 tion itself is followed by death in many cases. 



Symptoms. — The symptoms of rinderpest are not very characteris- 

 tic, and hence the diagnosis of a suspected case in the begiiming of 

 an invasion is attended with difficulties. Certain appearances which 

 are characteristic of one epizootic may be absent in another. Dif- 

 ferent observers are not quite agi-eed as to the most constant and 

 important. 



The period of incubation, i. e., the time elapsing between the expo- 

 sure to infection and the earliest outwafd symptoms, varies from 

 three to nine days. Then the first sign is a very high fever tem- 

 perature, which may reach 107° F. The heat of the skin varies in 

 different parts of the body, and may be felt at the base of the ears 

 and horns. Ref)eated chills are frequently observed. The pulse 

 reaches 50 to 60 beats per minute, and may rise to 90 or 100 in very 

 severe attacks. 



