SIMULTANEOUS TREATMENT OF PIGS 407 



immunity which should result from the double form of treatment 

 is not produced when the serum and virus are used in these little 

 fellows. It is better in this case to give the single or serum-alone 

 treatment, and six weeks or two months later on come back and 

 give the double method of treatment. In this way they are pro- 

 tected from the immediate danger of the attack, and at the later 

 treatment they are given a permanent protection which will enable 

 them to remain free from the disease as long as they may live. 



New Hogs Brought in From Other States. — In many sections 

 of the country it is necessary to go away some distance and 

 purchase new stock with which to fill up the feed lots. This may 

 be because of a bad spring, with death of a large number of pigs 

 from digestive and other disturbances, or may be due to the fact 

 that an outbreak of cholera has wiped out all the hogs and left 

 the feed lots empty. In bringing in hogs in this manner from 

 outside of the state, or, for that matter, in bringing new hogs to 

 the farm from any neighboring farm, it is always the proper plan 

 to have these animals treated with the double method before 

 moving them. Have the double method given right on the prem- 

 ises where the hogs are to be bought, and then move them to 

 your premises at the end of three weeks. 



In some cases this may not be possible, or may not be advisable 

 for one reason or another. In such cases have the animals double 

 treated just as soon as they arrive on your farm. It is then ad- 

 visable to keep them in a separate pasture for two or three weeks, 

 but with a first-class serum and a reliable virus they may be 

 turned directly into the infected feed lots without danger. 



Some would recommend that the animals in this case be given 

 the serum alone, and allowed to contract the germ infection by 

 being turned into the infected feed lot. While this method is in 

 a, measure satisfactory, it has some elements of uncertainty about 

 it that makes the use of the other plan more advisable. In turning 

 the serum-injected animals into this infected feed lot all is well, 

 provided every one of them comes in contact with enough of the 

 cholera germs to start up an attack in their body sufficiently 

 severe to start the manufacture of germ-fighting bodies. 



If for some reason, however, the germs of the disease did not 

 enter the body of some of these animals until after the effects 



