METHODS OF USING ANTI-HOG-CHOLEKA SEEUM 135 



have never seen a considerable number of animals 

 in one herd thus affected. 



Abscesses follow serum administration infre- 

 quently, and like the rapidly terminating type of 

 infection just described, they are usually asso- 

 ciated with faulty technique or conditions below 

 the average as far as sanitary surroundings of 

 the animals are concerned. They occur most fre- 

 quently in poorly nourished, weak animals, but 

 are not always thus limited, nor is it possible in 

 all cases to ascribe them to bad technique. The 

 bacterial flora of the particular surroundings in 

 which the immunizing is done seems to play an im- 

 portant part, but even this factor may be con- 

 trolled to a great extent by the free use of disin- 

 fectant. Dust contamination of serum and instru- 

 ments also favors abscess formation, and for this 

 reason one should work out of doors whenever 

 possible. Failure to distribute the dose of serum 

 thoroughly sometimes results in local inflamma- 

 tion, leading to abscess formation. Abscesses are 

 rare when the serum is not contaminated, when 

 care is used in administering it, and when the 

 treated animals are in reasonably clean quarters. 



Vaccination abscesses usually encapsulate and 

 form slowly, and although they sometimes reach a 

 considerable size and retard the growth of the 

 animal to some extent, they rarely threaten its 

 life or cause general symptoms of disease. If 



