468 HORSE, SWINE AND POULTRY DISEASES 



came sick unless some of the vaccinated hogs with which they asso- 

 ciated became severely ill ; indeed in a number of instances the pen 

 checks remained well, even though they associated with vaccinated 

 hogs exhibiting undoubted symptoms of hog cholera. From this it 

 appears that the immune serum not only possesses the power to pro- 

 tect hogs from a simultaneous injection of disease producing blood, 

 but that even in cases where too little serum is given it yet has a 

 marked tendency to lessen the infectiousness of the disease. Of the 

 58 pen checks exposed to vaccinated hogs, 6 contracted hog cholera 

 and 5 died. 



As a control experiment, 19 shoats were placed in the pens with 

 the hogs that were injected with disease-producing blood alone. Of 

 these, all became sick, 17 died, 1 was killed to secure blood for other 

 experiments, and 1 recovered. In other words, of the pen checks ex- 

 posed to hogs injected with disease-producing blood alone, 94 per 

 cent died, whereas only 8 per cent of the checks exposed to vaccinated 

 hogs succumbed. (B. A. I. Cir. 102.) 



Care Before Vaccinating. Cut down the ration two or three 

 days before vaccinating, feeding little corn. Keep the animals clean 

 and in dry, comfortable quarters, and if possible in disinfected pens. 

 If the weather is favorable, a dipping would be all right a few days 

 before vaccinating. (K. B. 163.) 



Treatment After Vaccinating. From the fact that there is 

 always more or less fever caused by vaccinating and more or less 

 danger of the animal becoming infected through the wound made 

 by the needle of the syringe, the following after-treatment would 

 suggest itself: Spare diet for three or four days, especially of corn, 

 but plenty of water, thoroughly clean and comfortable pens with 

 plenty of clean bedding, with absolutely no chance to get into mud 

 of any kind. The more mud and dirt the more danger. They should 

 not be dipped or operated upon for at least two weeks after vacci- 

 nating. (Kan. Bui. 163.) 



Conclusions on the Use of Cholera Serum. Since these results 

 were obtained the Department has brought this method of prevent- 

 ing hog cholera to the attention of the various State Experiment Sta- 

 tions and live stock sanitary boards throughout the country and has 

 proposed to them that they take up this work and prepare a serum 

 for the benefit of hog raisers, as the preparation of serum by the Fed- 

 eral Government on a large enough scale to supply the needs of the 

 entire country seemed to be impracticable. As a result of this, a 

 number of the States have taken up the work, and in practically all 

 cases where a thorough test has been made they have confirmed the 

 results obtained by the Department with this method. We therefore 

 feel safe in saying that this process will prevent hog cholera, pro- 

 vided due care is given to the preparation of the serum and to its ap- 

 plication. The serum preparation is of such a nature that it should 

 not be undertaken by farmers themselves, but should be under the 

 control of trained men who have had experience in bacteriology and 

 who are also thoroughly familiar with the diseases which affect hogs. 



