THE CAUSE OF CHOLERA 91 



ease. Among other organs especially affected are the kidneys 

 and bladder. The virus is apparently absorbed from the intestines 

 and carried by the blood to the kidneys, where it attempts to escape 

 from the body. As a result we find that the urine of animals 

 affected with cholera is also heavily laden with the ultramicroscopic 

 virus which produces the disease, and water, food, or earth which 

 comes in contact with this infectious urine becomes a source of 

 danger, in that it is capable of producing the disease in other ani- 

 mals which may eat food or drink water so contaminated. Here 

 again the factor of overcrowding becomes important, as in hogs 

 confined in small feed lots the food and litter are bound to become 

 more or less contaminated with urine and feces, and thus become 

 capable of transmitting the disease to other healthy animals in the 

 same herd. 



The virus of cholera is also present in large amounts in the 

 blood of sick animals, a fact made use of in the manufacture of hog- 

 cholera serum. This must not be forgotten, as anything which 

 comes in contact with the blood of an animal sick with cholera be- 

 comes most highly dangerous and will readily transmit the disease 

 to healthy animals. The importance of this fact can be best ap- 

 preciated when we observe the results that follow the feeding of 

 dead hog-cholera carcasses to other healthy hogs. A small amount 

 of the blood of a cholera animal if taken into the body of a healthy 

 hog will produce the disease. This explains the ease with which 

 the disease is carried for long distances by buzzards and crows. 

 The buzzard, in tearing the flesh of the dead cholera carcass, bathes 

 his talons freely in the blood of his prey, and then, when he flies 

 miles away to feast upon the body of some other dead animal, such 

 as a dead horse, which has been hauled out into a feed lot for the 

 hogs to devour, he carries on his talons a sufficient amount of this 

 highly infectio-us blood to infect the entire herd of hogs on the farm 

 to which he goes. 



In actual practice it has been found that as small an amount 

 as 5 drops of this infected blood is capable of producing cholera 

 when injected into healthy shoats, and in animals which are a little 

 bit weakened by improper feeding it would only require 1 or 2 

 drops of the blood from a dead animal to produce the disease in 

 them. 



