180 DISEASES OF SWINE 



farm. Cholera, once it gets into a herd, will usually attack e very- 

 hog on the place, and by far the larger percentage of them will die. 



It is a pretty safe estimate to say that at least 8 out of 

 every 10 will die unless serum be used early. Of those that are 

 left after an attack of the disease there are a great many that are 

 practically useless. They are hopelessly stunted, and if allowed 

 to live they simply grow up as runts, never being worth the grain 

 that it takes to feed them. It is a better policy to knock these 

 runts in the head, as they are not only of no value, but they may 

 also be a source of spreading the disease among healthy hogs. 



These runty hogs left after an outbreak of cholera seem to still 

 have, somewhere in their body, a local infection with hog-cholera 

 virus, and they are often discharging with their urine and manure 

 enough hog-cholera germs to start up the disease in a healthy 

 herd. 



I know of an instance of this kind where a farmer purchased a 

 half-dozen hogs from a neighbor at a public sale. In the herd 

 was one stunted shoat which had been through the cholera the 

 previous summer. When these hogs were taken home they were 

 placed in the pasture with the home herd. Two weeks later cholera 

 broke out on this farm and wiped out nearly the entire drove. 



In this case there was no other cholera in the neighborhood, 

 and it seems almost a certainty that this runty pig was the means 

 of infecting all the other animals. 



CHRONIC CHOLERA 



In some outbreaks of cholera nearly all of the cases seen are of 

 the chronic type. In other outbreaks the disease starts in as the 

 acute type, and, after the animals have for a few days shown signs 

 of the acute form, they may pass into a more mild and long-drawn- 

 out form — the chronic cholera type. 



In those outbreaks where the form of the disease is of a chronic 

 nature from the beginning, the animals develop signs of illness very 

 slowly, and may be coming down with the disease for several days 

 or even weeks before the owner notices that there is anything wrong 

 with them. As a matter of fact, in some cases the attack is so mild 

 in its symptoms that the animal may pass through the entire course 

 of the disease and never be noticed as actually sick. Perhaps the 



