FOURTEENTH ANNUAL YEAR BOOK— PART VI. 519 



The question of hog cholera seems always to be a most important one. 

 I was thinking while the gentleman was discussing the question of farm 

 credits, whether, if we could eradicate hog cholera from the state of Iowa, 

 there would be quite so many of us needing credit. We would not have 

 to make quite so many mortgages on our farms if we could eradicate this 

 plague. I hope to try to show you that we may be able to eradicate it 

 from the state of Iowa; in fact, that it can be eradicated from the entire 

 country. 



First, as to the nature of hog cholera. What is this disease commonly 

 called hog cholera? I want to emphasize that hog cholera, as we term 

 it, is a specific contagious disease which is communicated from one animal 

 to another by means of a specific virus. What this virus is, we do not 

 know. We have never been able to isolate and cultivate the virus of 

 hog cholera as we can cultivate the virus of a great many other animal 

 diseases. We do know, though, that the virus of hog cholera exists in 

 the blood of a sick hog, and that some way this virus, whatever it is, 

 leaves the body of the sick animal through the excreta, and animals 

 coming in contact with the virus by associating with the sick animal, or 

 by coming in contact with the virus after it has left the body of the 

 sick animal, contract disease and thus transfer spores from one animal 

 to another in the herd. We know that this differs from the virus of 

 many other animal diseases. If it is a bacterium it is very small, and 

 consequently it has been termed a filterable virus, so small that it can 

 pass the finest porcelain filter. We can readily filter out the germs of 

 most diseases. It may be a protozoon parasite, but it is something that 

 exists in the blood of the sick hog, and while we have been able to 

 manufacture a serum that will prevent it, we have not discovered exactly 

 what the virus is. Consequently, recognizing that it is a specific con- 

 tagious disease, I wish you to remember that the disease can not be 

 engendered in any other way except by means of this virus. If you keep 

 this virus away from your herd, your hogs will not contract hog cholera; 

 that is, it is not possible by feeding your hogs any unusual food or dam- 

 aged food, or anything of that kind, to start up a case of hog cholera; 

 you must have this specific virus. So I want you to get the idea out of 

 your heads that you are in danger of starting hog cholera if you feed 

 new corn, or that they get hog cholera from close confinement. You 

 can not get hog cholera except you have the presence of the hog cholera 

 virus, whatever that may be. , 



Henry AVallace : Can't you, by over-feeding green corn, pro- 

 duce a condition that looks awfully like hog cholera? 



Dr. Xiles: I don't think so. Hog cholera, like those other diseases 

 that Dr. Pearson has been telling about, we don't know the start of. 

 They were started by the Creator, the same as everything else. We 

 didn't have hog cholera for a good many years after the settlement of 

 the country, but we have every reason to suppose that it was imported 

 from England. We have been able to stamp out some of these animal 

 diseases. We have stamped out contagious pleuro-pneumonia and foot- 

 and-mouth disease. We have a horse disease that we have not been able 



