60 POULTRY DISEASES 



tion 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 in- 

 ternal parasites of birds; the large, round, in- 

 testinal worm ; the small, round intestinal worm ; 

 the gizzard worm; and the gapeworm, besides a 

 number of rare, or for other reasons, unimportant 

 worms, all of which will be described in turn. 



Ascaris Infiexa 



This parasite, sometimes called the Heterakis 

 perspicilhm, is commonly known as the large, 

 round worm. It is very common, having been 

 found by the author in twenty-four out of eighty- 

 seven autopsies. 



Description. — This intestinal parasite is round in shape and 

 whitish-yellow to white in color, varying from one to two 

 inches in length. There are two sexes, male and female, the 

 female heing considerably the larger. Fig. 18 shows the 

 actual size of the male and the female specimens from which 

 this drawing was made. Some few specimens are much larger 

 than the ones shown. 



Life History. The Ascaris infiexa reproduce by laying 



eggs, microscopic in size, which pass out to the ground with 

 the feces. Other birds become infested by drinking or eat- 

 ing food contaminated or soiled with the excrements of in- 

 fested birds. In this way one infested bird introduced into 

 the flock may spread the disease to all the other birds in 

 the flock. 



Symptoms of Infestation. — These parasites harm 

 the host by ingesting food during its digestion 

 by the host, thus robbing it to a certain extent. 

 A few worms may produce no noticeable effect 

 upon the health of the bird, but if present in large 

 numbers they cause serious trouble. It has been 

 found that the poison or excrementitious (waste) 

 matter given off by these and other intestinal 

 worms is absorbed and has a deleterious consti- 



