278 SWINE 



creek or any other form of running water flowing across 

 the country will carry these germs. If the diseased hogs 

 are allowed access to such a stream, sufficient germs may 

 be carried down the stream so that any hogs having ac- 

 cess to it farther down will be likely to contract the dis- 

 ease. 



In order to prevent its spreading after the disease once 

 gains entrance to a herd, the hogs should be divided up 

 into as small lots as possible which should be kept com- 

 pletely isolated from each other. If any of them are 

 already affected and show signs of sickness, these should 

 be entirely separated from the healthy ones, and the 

 healthy ones should be divided up into as small bunches 

 as possible and kept in separate pens. Then by exercis- 

 ing great care in going from the diseased hogs to the 

 healthy ones, — not using the same clothes or the same 

 apparatus for feeding, — there will be the least danger of 

 communicating the disease to other hogs in the herd. 



Great care should also be exercised when new animals 

 are brought into a herd. It is usually well to quarantine 

 these for a jleriod of about three weeks so as to be sure 

 that they do not have the cholera, before they are put into 

 the general herd. Unaffected hogs may be bought from 

 entirely healthy herds, but this is not always true, as 

 the herds from which the hogs are purchased may have 

 been recently infected and the disease not yet developed 

 so as to be noticed. The period of incubation, or the 

 period from the time the disease germs are taken into the 

 system to the time that the disease appears, is from one 

 to two weeks. Consequently, diseased animals may be 

 bought when a herd is apparently entirely healthy. Fur- 

 thermore, healthy individuals shipped across the country 

 may come in contact with the disease in various forms; 



