CHAPTER X. 

 PARASITES IN THE INTESTINES. 



HELMINTHIASIS. 



In small animals parasites in the digestive tract are very 

 numerous. They pass rapidly through the anterior portion 

 of the digestive tract, which prevents their becoming fixed; 

 also in this portion of the canal secretions for their proper 

 development are lacking. In the stomach, owing to its 

 acidity, they do not remain long, but are either destroyed 

 or pass into the small intestines. In a few instances, how- 

 ever, they may burrow underneath the mucosa of the stom- 

 ach. The intestines are favorable for the development of 

 parasites, owing to their length, the presence of an abun- 

 dance of fluid, and the slow peristaltic movement of the 

 bowels which does not materially interfere with their fixation 

 and development. The majority of the parasites are found 

 in the small intestines; fewer are found in the cecum, colon 

 and rectum. Each species of parasite has its particular 

 location, and unless in unusual numbers, or under abnormal 

 conditions, they will be found infesting an exclusive portion 

 of the bowel. Parasites are frequently found in very large 

 numbers, and produce serious disturbances in the intestinal 

 tract, depending upon the species of parasite and the animal 

 infested. The most common parasites found in the intestinal 

 tract belong to the animal kingdom, and are: Cestoda; 

 Nematoda; Acanthocephalai Coccidia. 



T.ENIASIS. 



Ccxioda . 



The dog is the favorite host of the taenia 3 . They occur in 

 this animal in considerable numbers, sometimes so as to 

 13 



