APPENDIX 287 



and rules are declared for a guide in judging the re- 

 sults of serum tests : 



Principle : It is practically impossible in many cases 

 accurately to differentiate between hog cholera, pneu- 

 monia, and other conditions affecting hogs, without the 

 aid of an autopsy as well as applied laboratory technique 

 and certain experiments which may be necessary to de- 

 termine the causative agent responsible for the condi- 

 tion. Therefore, when healthy pigs are selected for test- 

 ing anti-hog-cholera serum any abnormal condition 

 which may arise in the pigs subsequent to their inocula- 

 tion should be regarded as due either to the virus used 

 or, in the case of the serum-treated pigs, to the fact that 

 the serum does not protect, unless the condition is defi- 

 nitely known or can be shown to be due to some other 

 cause. 



Paragraph 2. The following rules shall be observed in 

 disposing of anti-hog-cholera serum which has been sub- 

 jected to the tests prescribed by this order: 



Rule A. A serum test shall be declared a "No test" 

 if any one of the following conditions obtains : 



1. When any of the serum-treated test pigs or both of 

 the control pigs become visibly sick on or before the 

 fourth day after the time of inoculation. 



2. When both of the control pigs do not exhibit symp- 

 toms of hog cholera at some time during the test period 

 as described in rule D of this paragraph. 



3. When neither of the control pigs exhibits symp- 

 toms of hog cholera subsequent to the fourth day and 

 within 7 days after the time of inoculation as described 

 in rule D of this paragraph. 



4. When one or both of the control pigs exhibit symp- 

 toms of hog cholera within 7 days, as prescribed in rule 

 D of this paragraph, but do not become sick to a degree 

 sufficient to result in death within 15 days after the 

 time of inoculation. 



