262 DISEASES OF SWINE 



had the run of the cholera feed lots as well as their own might be 

 capable of carrying the disease across the road into his lots. 



As has already been stated on preceding pages, the infection 

 of cholera is not carried for any great distance through the air, and 

 rarely indeed would be carried as great a distance as that which 

 existed in this case by means of air alone. The only direct com- 

 munication between the two feed lots was by means of the flock 

 of chickens mentioned, and it would seem almost a certainty that 

 they were the means of bringing the disease to A's animals. 



In connection with this outbreak there was another incident 

 that occurred that is worthy of note here. Both of these men had 

 a fairly good knowledge of cholera and its catching nature. They, 

 accordingly, used every precaution to keep the disease from spread- 

 ing. All dead animals were burned every morning on B's farm, and 

 those that died on A's before shipment were immediately burned. 

 Both feed lots were afterward cleaned most thoroughly and sprayed 

 with a strong disinfecting solution. As a result the outbreak was 

 kept on these two farms and made no advance to adjoining farms. 

 This is a striking contrast to the results that we have already seen 

 in our investigation of other outbreaks where these precautions 

 were not taken, and where the outbreaks have rapidly extended to 

 involve a wide area, producing enormous financial losses as well as 

 very great damage to the hog-raising industry for years to come 

 in these cholera-swept districts. 



As further proof of the effects of proper sanitary efforts it 

 might be added that A, mentioned above, brought a new drove of 

 hogs upon his premises three months later and turned them into the 

 infected pens. As we have already seen in cases where the pens 

 have not been thoroughly cleaned out and properly disinfected, 

 this practice would mean the death of a large percentage of the new 

 animals within three weeks after they had been introduced into 

 these pens. In this case, however, there was not a sign of cholera 

 in the new animals, and we can explain this fact only by the thor- 

 ough cleaning which was done after shipment of the infected ani- 

 mals, and the proper disinfection of the pens which followed this 

 cleaning-up process. 



In the farming district of the Middle West and, in fact, in 

 practically all parts of the country very frequently we find a 



