134 HOG CHOLEKA 



munization. Occasionally rough handling during 

 the process of vaccinating will injure an animal, 

 but this is not to be charged to the effect of serum. 

 Sometimes, especially in very young pigs, a tem- 

 porary stiffness or lameness exists for a day or 

 two following treatment, but this is exceptional, 

 and usually it is of little consequence. Large 

 quantities of cold serum, especially when the dose 

 is not well distributed, sometimes cause this 

 trouble in an aggravated form. The obvious pre- 

 cautions are to use due care in injecting, and to 

 warm serum that is to be administered to young 

 pigs in cold weather. A temperature approaching 

 blood heat is desirable, and may be secured by 

 placing the bottles in warm water. 



Very exceptionally there is observed, immedi- 

 ately following serum administration, a rapidly 

 spreading local infection often involving an entire 

 quarter and encroaching on other parts. There 

 is acute lameness in the affected quarter. The 

 area involved is either doughy in consistency, or 

 else gas formation is evident, and under both con- 

 ditions there is pronounced edema. The skin 

 usually assumes a purple hue. As a rule, animals 

 thus affected die in a short time. We have seen 

 but a limited number of such cases, and with one 

 exception, all could be traced to gross carelessness 

 in technique, or to working conditions which ren- 

 dered even average technique impossible. We 



