774 BOARD OF AG1;K LLTLKE, 



The trerms of some diseases, as glanders, can live I'ur only a short 

 time outside of the body, and hence can only lie conveyed by close cou- 

 tact or by animals being placed in the stalls or pens where other cases 

 of the disease have been. Such diseases can be stamped out by slaughter 

 and rigid quarantine. Hog cholera and swine plague do not belong to 

 that class of diseases. In other diseases, of which anthrax Is a type, the 

 germs can live and multiply outside of the body for a long time and be 

 able to produce the disease when a favorable opportunity arises. Anthrax 

 has been known to occur as a result of eating the forage from the graves 

 of former victims. There are observations which seem to show that the 

 germs must have lived in the ground for at least seventeen years. The 

 experiments with the hog cholera germs do not show them to possess the 

 same resistive qualities attributed to anthrax, but there are many who 

 do believe that they have a very similar life history in nature. If such 

 be the case, then the problem of how to control the malady becomes all 

 the more difficult. 



Similarity to Typhoid in the Human Subject.— Our present knowledge 

 of the germ tends to show that in many respects its life history is like 

 that of the typhoid fever germ. No one would claim that the diseases 

 are identical, or that typhoid is as virulent or contagious as hog cholera, 

 but there are points of resemblance. The lesions in the intestines, 

 lymphatic glands and spleen in the two disease are so much alike that 

 cholera is often called pig typhoid. When blood from a typhoid patient 

 is placed in a culture of typhoid germs it causes them to cling together. 

 When blood from a cholera hog is placed in a culture of cholera germs 

 it causes a similar reaction. Typhoid germs are rarely ever found outside 

 of the body and stools of a sick patient, but it is well established that all 

 epidemics have their origin in the water supply. Epidemics of typhoid 

 fever occur in cities, and no matter what may be the source of the water 

 supply— river, lake or wells— it will be found that it is polluted with the 

 discharges from people. Typhoid fever can always be arrested by se- 

 curing pure water. The researches of the Indiana Experiment Station 

 have demonstrated that the disease is also water Tijorne. In a series of 

 townships in this State it was found that from 33 to 200 per cent, more 

 hogs were lost along the rivers and streams than at a distance from three 

 to teil miles away from the stream. This could be attributed to the 

 more general use of surface water. No such conclusion must be reached 

 that the disease is only water borne, for we have seen the disease pass 

 up river as well as down and the pigs in a whole section of the country, 

 from one to three miles wide, and from Ave to seven miles long, become 

 affected simultaneously after a rain. 



Less is known concerning the life history of the germs of swine plague 

 than of those of hog cholera. It is known that the disease is more dif- 

 ficult to prevent than cholera; its spread is less liable to be influenced 

 by hygienic measures and it seems to be air borne. Germs very much 



