HOG-CHOLERA 85 



which is produced by some form of germ. These germs are not al- 

 ways capable of demonstration. For instance, hog-cholera is 

 classed by practically all writers as an infectious disease, but no 

 one can demonstrate the germ which is the cause of the condition. 

 Hog-cholera shows so much resemblance to other infectious dis- 

 eases, however, that it is practically a positive conclusion that 

 some germ is present which is causing the disease, but which has 

 so far eluded the efforts of the most scientific workers to show its 

 presence, even under the microscope. 



It is characteristic of these infectious diseases that they can 

 be transmitted from the sick to healthy herds. Some infections are 

 very rapidly carried from one animal to another. In fact, with 

 many of them, mere contact in the same pen with the sick seems 

 sufficient to transfer the infection. Such diseases as this are classed 

 as "catching" or contagious. In other infectious diseases it is 

 necessary for the germ to be carried in some manner from the 

 body of the sick to the well animal in order to transmit the 

 disease. 



With this explanation, we are now ready to take up some of 

 the important diseases of this class, of which hog-cholera is, by all 

 means, the most common and most interesting to both veterinarian 

 and stockman. 



HOG-CHOLERA 



Hog-cholera is a severe, acute disease of swine, which is caused 

 by an invisible germ, and which is recognized by the production 

 of severe symptoms, principal of which are loss of appetite, cough, 

 diarrhea, red blotches on the skin, and a very peculiar turkey-egg 

 spotting of the kidneys, seen when the body is cut open after death. 



HISTORY 



Hog-cholera was no doubt first brought into this country by the 

 importation of hogs from Europe in the latter part of the 18th 

 or early part of the 19th century. The early history of the disease 

 in the United States is not definitely recorded in the literature of 

 that time, but this disease, like many others, seems most likely to 

 have been brought into the country from England. Many of our 



