CHAPTER IX 



PAEASITES 



The subject of parasitic attacks on the lower animals, 

 especially the herbivora, is of extreme importance. Losses 

 from this cause are very heavy, and in some years a verit- 

 able plague. 



Both within and without the profession insufficient 

 attention has been paid to this matter, either from a 

 hygienic or therapeutic point of view. There is, for 

 example, no disease which causes such a heavy monetary 

 loss as the warble fly, but in spite of the fact that we know 

 every stage of its life history, how to effectually deal with 

 the affected animals, and the methods of preventing attack, 

 yet little or nothing is done. Had warbles been due to a 

 minute microbe, it is quite possible that a cry would have 

 been raised for an antitoxin ; but being due to so common 

 a thing as a maggot, it is neglected and allowed to run its 

 course, with practically no attempt at prevention. 



The ravages of stomach and intestinal parasites have 

 also received insufficient attention. Heavy losses result 

 from these, yet neither prevention nor treatment have 

 received the consideration they deserve, and the same 

 indeed applies to most internal parasitic diseases. 



It is only those directly contagious that have occupied 

 any position of importance, yet none of these are fatal, 

 while those of the stomach and intestines, liver and 

 lungs, are frequently so. The life history of these latter 

 parasites prevents them being directly infectious, and the 

 necessity for an intermediate host gives a false sense of 



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