STATE HYGIENE 49T 



that the immunity produced is but temporary, lasting only 

 a few months ; but these few months may be quite sufficient 

 to enable the disease to be eradicated. 



The immunising substance does not exist in bile taken 

 from animals recently attacked, it is always present when 

 taken from those at the point of death. 



The other method of protection is by the use of serum 

 from animals which have been artificially immunised, and 

 fortified to such an extent that instead of a single drop of 

 blood producing the disease, they are capable of standing 

 nearly eight quarts of virulent material being introduced 

 into their system without manifesting any disorder. But the 

 process of hyper-immunisation is a long and tedious one, 

 and has to be gradually brought about. Once the serum is 

 obtained and its strength known, viz., how much of the 

 serum will neutralize a given amount of virulent blood, 

 the inoculation may proceed. 



The principle in serum inoculation is that with the 

 serum is administered a dose of virulent blood, both being 

 simultaneously injected. The serum must be strong and 

 reliable, 30 c.c. of strong serum and 1 to 2 c.c. of virulent 

 blood confer a lasting immunity. 



It must be borne in mind that the use of virulent blood 

 is not without risk of conveying other affections, hence in 

 South Africa it was found that though immunity against 

 Cattle Plague was obtained, yet Texas Fever (red water or 

 hsBmoglobinuria) was readily conveyed, likewise other 

 diseases, such as anthrax and quarter-evil. Where these 

 diseases do not exist in a country, or only to a limited 

 extent, the risk is correspondingly reduced. 



Serum may also be used as a curative agent for Cattle 



Plague, but a consideration of this matter is outside the 



scope of this work. 



LEGISLATION. 



The Diseases of Animals Act, 1894, and the Cattle Plague Order 



of 1895. 



Notice of Disease. — This is to be given to a constable of the police 



area with all practicable speed by the person having, or having had, in 



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