HOG CHOLERA: PREVENTION AND TREATMENT. 25 



good serum, and give plenty of it. Enough serum should be given 

 to prevent any signs of illness in the treated hogs. To get a last- 

 ing immunity it is not necessary to render the hogs visibly sick from 

 the injection. Apparently just as firm immunity is secured when 

 hogs show no symptoms of illness as when they are made sick by 

 the injection. This treatment should be handled carefully, and 

 those who have studied this question agree that the simultaneous 

 inoculation should be administered only by competent veterinarians 

 or by skilled laymen who have had adequate training in its use. 



The prolonged immunity caused by the simultaneous inoculation is 

 much to be desired for several reasons. It prevents the recurrence 

 of cholera in the treated hogs; it eliminates the additional expense 

 of re-treatment; and, in the case of infected premises, it affords a 

 better opportunity to eliminate the germs of the disease, thus remov- 

 ing a source of danger from the neighborhood. 



It is of the greatest importance, when applying the simultaneous 

 inoculation, to give an ample dose of serum. Many of the commer- 

 cial serums bear labels which show 7 the smallest dose that is rec- 

 ommended for use. In no case will harm be done by increasing 

 this dose. It is much better to give a little more serum and save 

 the treated pig at an added cost of a few cents than to lose it 

 through failure to give enough serum. In general the dose of 

 serum required in the simultaneous inoculation may be said to de- 

 pend upon the age, weight, and condition of the animal, but the 

 amount of serum required is not in direct proportion to the weight, 

 for small pigs and shoats require a larger dose in proportion to their 

 weight than older animals, and in all classes of hogs which show 

 high temperatures but no other evidence of disease, a larger dose 

 of serum should be given than when healthy hogs are being treated. 

 No pig should receive less than 10 cubic centimeters of the ordinary 

 commercial serum, and 80 cubic centimeters may be regarded as a 

 sufficient dose for a healthy hog weighing 200 pounds or over. 



The syringe used for injecting the virus should be in perfect 

 order and care should be taken to see that the amount of virus 

 prescribed in the dose table is actually injected into and retained 

 by each animal. 



TREATMENT OF HERDS. 



Healthy herds. — No definite rule can be laid down as to the ne- 

 cessity for treating healthy herds or as to the method to be used 

 in treating them. In general it can be said that the necessity for 

 the treatment of healthy herds depends upon surrounding condi- 

 tions, that is, the proximity of cholera and the ability of the farmer 

 to protect his herd from the infection. It has been demonstrated 



