, ANIMAL PARASITES IN THE INTESTINES 133 



colic and emaciation, especially in colts). In still rarer 

 instances they produce perforation of the stomach and 

 peritonitis. Once in a while bots induce inflammation of the 

 rectum or even prolapsus recti, and still more rarely they may 

 enter the brain, larynx, and other organs. 



Treatment. — The only agent of any value to eliminate 

 the bot larvae is the disulphid of carbon. It should be 

 administered on an empty stomach in capsules in doses of 

 5 iiss, four doses of which are given, with an hour between 

 each. After twelve to twenty hours administer a good 

 purgative. 



Prophylaxis. — Prevention consists in destroying the bot 

 flies when observed about horses and by removing the eggs 

 from the hairs once a week with a sharp knife. Cleaning 

 out of the underbrush in woods, pastures, along the road- 

 ways, and in the fields is contributory to this elimination. 



SPIROPTERA. 



These nematodes appear in the stomach of the horse and 

 ass, where they form tumors in the pyloric portion, varying 

 in size from a hickory nut to a hen's egg. When a tumor is 

 incised the thin, thread-like worm appears. They sometimes 

 induce gastritis and colic. 



Spiroptera strongylina occurs in the stomach of swine 

 and sometimes induces an enzootic gastritis. 



ANIMAL PARASITES IN THE INTESTINES. 



Tapeworms (Cestodes)—IAie Cycle. — In its development 

 the tapeworm passes through two stages, viz.: the cyst or 

 larval form and the adult tapeworm. Usually the cyst" 

 is. found in one animal host and the tapeworm in another. 

 The hosts are usually not even of the same species. As an 

 example, the tapeworm Taenia ccenurus has for its host the 

 dog, while the larval stage, the Ccenurus cerebralis, has for 

 its host usually the sheep. The Taenia cucumerina, the 

 common tapeworm of the dog in its cyst form, is harbored 

 by the common dog flea (Pulex serraticeps). 



Digitized by Microsoft® 



