PREDISPOSING CAUSES 119 



€attle are shipped from the large stock yards in cars which have 

 been recently used for the shipment of hogs which may have been 

 infected with cholera. It also frequently happens that these cars 

 are not thoroughly cleaned and disinfected before being reloaded 

 with cattle. As a result of this practice the cattle come on to the 

 place bringing with them infected manure and bedding from these 

 cars. It naturally follows that within a few days there is an out- 

 break of cholera among the hogs in these feed lots. 



In many instances the same loading chutes are used at smaller 

 stock-yards for cattle, sheep, and swine. These chutes and pens 

 are practically always infected, and the result is carrying of hog- 

 cholera virus by the cattle and sheep which pass through them 

 on to the feeding farms. Cholera invariably will result from such 

 practices, and thousands of animals die as a result of this form of 

 neglect every season. 



It should be remembered that the loading pens and chutes 

 of pubHc stock-yards are practically always infected, and that 

 any animals passing through these pens will carry the infection 

 with them to their new pastures. 



Stock cars are always a menace to animal health unless they 

 have been thoroughly disinfected after each unloading. It is a 

 wise practice, and one that should be always insisted upon, to have 

 cars thoroughly cleaned and disinfected before loading them with 

 cattle, sheep, swine, horses, or any other animals that are to be 

 taken back to the farms for feeding purposes. Hog-cholera is only 

 one of many diseases which may be transmitted by this means of 

 infection. 



(20) Driving Hogs On Public Roads. — When cholera makes its 

 appearance in a herd it is the common practice to ship out all those 

 animals at once which are of marketable size and which do not show 

 marked symptoms of the disease. In many communities it is the 

 practice to take the hogs to the loading yards by driving them along 

 the public road. This should never be allowed, and especially 

 should it not be allowed in the case of swine where there is any 

 likelihood of cholera being present. 



Frequently sick shoats will die along the route, and nearly al- 

 ways there are one or more sick animals in the lot, and these are 

 distributing infectious manure and other discharges along the road- 



