ANIMAL PARASITES IN THE INTESTINES 135 



Treatment. — In horses the most valuable tapeworm agent 

 is tartar emetic (g ss) daily for three of four days. Turpen- 

 tine (Bj-ij) is a good tseniafuge. It should be given in milk 

 or oil to prevent blistering the mouth or throat. 



In lambs picrate of potash (gr. ij-vj), kooso (gr. ij-iij) 

 or male fern (5j) are recommended. Taeniafuges should 

 be given on an empty stomach and followed in twelve to 

 twenty hours by a good purge. Treatment is successful only 

 when the head of the tapeworm is also removed. 



Prevention. — In dealing with an enzootic of tseniasis it is 

 advisable to give the animals plenty of good, nutritive 

 food and excellent care. Sometimes these alone are all that 

 is necessary. Obviously, cysts and tapeworms should be 

 destroyed as a preventive measure. 



Bound-worms (Ascarides). — The ascarides or round- 

 worms resemble earthworms somewhat in form. The life- 

 cycle of these parasites has not yet been fully determined. 

 Unlike the tapeworms, they do not seem to require an inter- 

 mediate host. The transmission to susceptible animals 

 occurs through the ingestion of fecal matter containing the 

 eggs and not through drinking water. Milk, however, can 

 become contaminated and therefore very young animals 

 are infested. The development of the embryo from the egg 

 is very rapid. For instance, the egg of the Ascaris megalo- 

 cephala of the horse will develop a complete embyro in three 

 days. The following are the varieties of ascarides: 

 Horse: Ascaris megalocephala. 

 Ox and Swine: Ascaris lumbricoides. 



Symptoms.— In most cases round-worms produce no 

 symptoms. * Occasionally, however, if large numbers of them 

 are present in the intestine they will produce symptoms of 

 chronic intestinal catarrh, obstruction of the bowel or more 

 rarely hemorrhagic enteritis. A few exceptional cases of 

 bowel perforation with fatal peritonitis have been due to 

 round-worms. At times they may' block up the bile ducts 

 and produce icterus. Besides acting in a mechanical way it is 

 very possible that round-worms eliminate a toxic substance 

 which acts upon the nervous system, producing symptoms of 

 epilepsy, tetanus or paralysis (anaphylaxis?). In cajves an 



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