116 ANNUxVL REPORT OF THE Off. Doc. 



a cow when she is iiot giving milk, pi-acticallj all danger of injury 

 to tbe udder would be avoided. In this case, the vaccination might, 

 indeed, be applied directly to the skin of the udder. From the large 

 experience that has been had in the vaccination of cattle for the 

 production of vaccine virus, it is evident that no serious results 

 need be anticipated from such vaccination as is here proposed, pro- 

 vided the work be done in a cleanly and surgical manner. 



Hog Cholera. — Hog cholera has occurred in the following coun- 

 ties: Adams, Bradford, Bucks, Clinton, Columbia, Delaware, Frank- 

 lin, Lancaster, ]Montgomery, Philadelphia and Somerset. Hog 

 cholera is not now stationary in any part of Pennsylvania. Out- 

 breaks, as they occur, are controlled and the disease is usually 

 eradicated before it has spread much. 



The occurrence of hog cholera, in almost ever}' instance, may be 

 traced directly to the introduction of hogs from other states. Some 

 of them, no doubt, are diseased when shipped, others contract the 

 disease in the cars and in the pens and stock yards through which 

 they pass. There is so much hog cholera in the great swine- 

 producing states of the Middle West that it is impossible to keep 

 stock cars and stock yards free from infection from this 

 disease excepting by frequent and thorough cleansing and disin- 

 fection. Unfortunately, this is not practiced and so there is great 

 risk in shipping hogs that are not intended for immediate slaughter. 

 Hogs that are to be kept and fed should be either purchased in 

 the neighborhood from farms that are known to be free from 

 cholera, or, if purchased at a distance, and in a region that is 

 known to be free from infection, they should be shipped in box cars 

 that have not been used for the shipment of live stock, and they 

 should by no means be unloaded at public stock yards or pass 

 through the chutes or pens that it is customary to use for hogs. 



No practical raetliod for immunizing hogs against hog cholera 

 has yet been devised, although this subject is still receiving careful 

 attention at the hands of experts employed by the Bureau of Animal 

 Industry. 



When hogs are purchased for addition to established herds, they 

 should be placed under a system of quarantine and kept entirely" 

 apart from the hogs formerly on the premises until a period of ten 

 weeks has elapsed. It would also be well to dip purchased hogs 

 in an antiseptic solution made with one of the cold tar disinfect- 

 ants before they are permitted to associate with healthy animals. 

 The object of dipping is to destroy disease germs that the animal 

 may carry on the surface of its body, and also to destroy parasites. 

 Should a purchased hog kept in this way develop cholera, the ex- 

 tension of the disease to the sound herd could be prevented; 

 whereas, if the purchased animal wefe introduced t|,| 0?»cf; juto the: 



