SECTION IV 



Internal Parasites 



Parasites infesting the intestinal canal of fowls 

 are harbored by most fowls, and serious infesta- 

 tions by these parasites are by no means rare. 

 These parasites are commonly spoken of as worms. 

 Other internal parasites, such as gapeworm and 

 air-sac mite, while not so common as the intestinal 

 worms, are by no means unknown, and have the 

 same possibilities of serious infestation. 



Intestinal parasites in small numbers infest all 

 fowls without doing perceptible harm, but there 

 is always the possibility that conditions for their 

 propagation may become so favorable as to turn 

 the .mildest infestation into a devastating para- 

 sitism. Indeed, this very thing has occurred num- 

 berless times, and not a few flocks have been en- 

 tirely destroyed by it. The death of any bird from 

 the effects of internal parasites should be looked 

 upon with apprehension. 



Internal parasites may be classed under four 

 orders, as follows : Nematodes, or round worms ; 

 Cestodes, or flat, ribbon-shaped segmented worms ; 

 AcanthocephcUa, or thorn-headed worms ; and the 

 Trematoda, or the flat leaf-like worms, called 

 flukes. 



IMPORTANT ROUND WORMS 



These are the commonest of internal parasites ; 

 they may be found in the ceca of nearly all fowls, 

 and usually in other portions of the bowel. When 

 numerous they may seriously interfere with di- 

 gestion and lessen nutrition, and by their irrita- 



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