XXXVIII. 

 PARASITIC DISEASES OF THE HORSE. 



Parasites are distinguished as endoparasites, or entozoa, when 

 living in the interior of their hosts, and as ectoparasites, or ex- 

 tozoa, when external. We will confine our attention entirely to 

 entozoa, of which among the most important are those known as 

 worms. These include not only round worms resembling the 

 earth worms, but also worms resembling a band or a tape (tape 

 worms), or a leaf (flukes), and thorny-headed worms. We have 

 here to deal with the parasites of the horse. Those of other 

 animals are treated elsewhere in this work. 



The most important parasite is the tape worm, taenia perfoliata. 



They contain four sucking discs, in length from one to five 

 inches, and are found in the large intestines. 



Symptoms. — There are no special symptoms of diagnostic 

 value. The animal is generally in good condition when affected. 

 He becomes weak, unable to keep up, sometimes running and 

 stumbling in going down hill, or falling headlong. 



Treatment. — Give the oil of male shield fern, in gruel or ball, 

 from one^half to one ounce, or areca nut, one-half ounce. The 

 bowels should first be cleared out by giving bran mashes and 

 fasting. A sharp purgative should be administered about twelve 

 hours after giving the worm medicine. 



ASCARIS MEGALOCOPHALA. 



This is a nematode or round worm, resembling the common 

 earth worm in size and shape. The male is shorter than the 

 female, and the average length' is from six to eight inches. 



They are found in the entire length of the alimentary canal, 

 but generally in the small intestine. 



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