THIRTEENTH ANNUAL YEAR BOOK— PART IV 155 



capable of giving a certain amount of an anti-toxin, or a certain number 

 of anti-bodies which are in the hog cholera serum. If the tail is short, 

 and you don't re-hyiDer-immunize, ten days after the third tail bleeding, 

 you bleed him from the throat, and get all the blood he has. His carcass 

 is pork, accepted by the government inspector, and claimed by all lo 

 be the purest carcass of pork that goes to the market, unless he might 

 have abscesses. If he has, the government inspector is there to see 

 if he has any local abscesses from any of the injections that would 

 condemn the carcass. The clot is taken out of that blood, and the 

 serum of the blood goes to market, with a small percentage of preserv- 

 ative added to keep it. 



You have heard something about the testing of serum. A fairly practical 

 test calls for three pigs, and preferably from the same litter, in the hope 

 that they will be as near alike in all their characteristics and in their sus- 

 ceptibility as it is possible to get three pigs. You may get in any litter of 

 pigs one that is a natural immune against cholera and won't take it at 

 all, but that is the exception. To No. 1 you give a full inoculated dose of 

 cholera virus — nothing more. He should die in just ten days, if you have 

 good virus — that is, in summer weather; in cool fall weather a virus pig 

 may go to twelve or even fourteen days, and yet your virus may not be 

 weakened at all. In the summer time, when the temperature is around 100 

 degrees, he may die in nine days, and once in a while in eight. No. 2 we 

 give the full dose of virus and half a dose of serum; and No. 3 we give the 

 full dose of virus and the full label dose that goes with every serum bottle. 

 No. 2 may be very sick and pull through. No. 3 should not be very serious- 

 ly disturbed. He may miss a meal or two, but is rounded out in a few days 

 in fine shape. If No. 2 lives and No. 3 is not very sick, you may say you 

 have good enough serum to send out. 



The serum receives a little backset from one fact that I want to remind 

 you of, and that is that the government starts us out on a half dose. If 

 you have a serum of the highest potency, that original. government dose 

 will work very well; but every laboratory in the country has now on its 

 label practically double the dose that we started .with, and I think that 

 counts for better results in most communities where the serum has been 

 used for several years. The serum alone does not sicken a hog, and there 

 is no possible way that you could inoculate a hog with good serum. 

 The serum simultaneous gives the hog a mild dose of cholera and a dose of 

 serum to carry him through it. It is the only treatment that should be 

 called vaccination, because it produces the disease in a mild form. 



You all know that pregnant sows are apt to abort in cholera. We 

 have had some history of the simultaneous treatment causing abortion, 

 HO wo sometimes warn a man against the use of it on sows well advanced 

 in pregnancy. 



Some years ago several men started out on the theory that they could 

 I'reed a rac« of immune hogs. That matter has had a good deal of atten- 

 tion since the serum treatment came in vogue. Doctor Reynolds, of Min- 

 nesota, has experimented along this line, and there is a peculiar thing 

 about this transmitted immunity — what there is of it — to the young. 

 The hyper-immune — the one that has produced our serum — will not give 



