412 DISEASES OF SWINE 



With a low-grade serum which has been made under dirty con- 

 ditions it is not unusual to have abscesses develop as a result of the 

 carrying in of pus germs with the serum itself. The proper way 

 to avoid this form of abscesses is by refusing to use a serum that 

 comes from plants that have not received the approval of the United 

 States Bureau of Animal Industry with respect to the sanitary 

 conditions under which they are operated. 



Another fruitful source of abscess formation is the use of needles 

 and syringes which have not been properly boiled before use. This 

 is a very important point and one that should never be neglected. 



GENERAL SUMMARY OF USE OF SERUM 

 From a consideration of the facts which have now been brought 

 out concerning the use of serum, we are led to the following con- 

 clusions regarding its powers and the methods for its use : 



(1) Hog-cholera serum is a substance which is made by taking 

 the blood of an animal which has developed in its body the ma- 

 chinery necessary for the manufacture of enormous numbers of 

 germ-fighting or germ-destroying substances, known as antibodies. 

 This blood is simply treated so as to remove the parts which cause 

 clotting, and is then ready for injection into the body of a healthy 

 animal for the purpose of overcoming the effects of an attack by the 

 cholera germs. 



(2) This serum contains nothing that can in any way be harm- 

 ful if properly made and kept clean, so as to be free from any 

 germs or other disease. 



(3) Serum, being a harmless substance, can be used in almost 

 any dosage without producing any harmful effects. The main 

 danger lies in not giving enough. There is no danger of giving an 

 overdose of the remedy. 



(4) In injecting serum there are a number of places in the body 

 where it may be introduced. The most commonly used of these 

 locations is to inject the serum with a long needle and syringe 

 deep into the muscles on the inner side of the ham. The absorp- 

 tion of serum following this method of injection is believed to be 

 a little better than from any other region of the body. The ob- 

 jections to this method are the loss which results to the packers 

 from the development of abscesses in the hams when ham injection 



