SECTIOX IV 



INTERNAL PARASITES 



Parasites infesting the intestinal canal of fowls are har- 

 bored by most fowls, and serious infestations by these para- 

 sites are by no means rare. These parasites are commonly 

 spoken of as worms. Other internal parasites, such as gape- 

 worm and air-sac mite, while not so commoix as the intestinal 

 worms, are by no means unknown, and have the same pos- 

 sil)ilities of serious infestation. 



Intestinal parasites in small numbers infest all fowls with- 

 out 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 occured numberless times, 

 and not a few flocks have been entirely destroyed by it. The 

 death of any bird from the effects of internal parasites should 

 be looked upon with apprehension. 



Flocks infested with large numbers of round worms are 

 unprofitable in the extreme. The birds are unthrifty, appear 

 unkempt and suffer from diarrhea and constipation. Young 

 fowls are most severely affected. 



Internal parasites may be classed under four orders, as 

 follows : Nematodes, or round worms ; Cestodes, or ribbon- 

 shaped segmented worms; Acanthocephala, or thorn-headed 

 worms; Trematoda, or flat leaf -like worms, called flukes. 



IMPORTANT ROUND WORMS 



Kound worms 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 seri- 

 ously interfere Avith digestion and nutrition, and by their ir- 

 ritation of the intestine cause a stubborn diarrhea. Rarely 

 they become so plentiful in the intestine as to wholly obstruct 

 it. 



The round worms include four important internal parasites 

 of birds ; the large, round, intestinal worm ; the small, round 

 intestinal worm ; the gizard worm ; and the gapeworm, be- 

 sides a number of rare, or for other reasons, unimportant 

 worms, all of which will 1)e described in turn. 



Ascaris Inflexa 

 This parasite, sometimes called the Ileteralis perspicillum, 

 is commonly known as the large, round worm. It is very com- 



