i^22 PARASITES OF THE DOMESTIC ANIMALS 



upon the susceptibility and favorable hostage offered by the individual 

 to the parasite. 



It follows that preventive measures should be based upon the life 

 history of the species to which such measures are applied. Where 

 this is known and intelligently taken advantage of, the problem of the 

 eradication of the parasites becomes much easier of solution than it 

 otherwise would be. For the same reason, more detailed reference to 

 control is reserved for application to particular cases in the pages to 

 follow. 



The nematode parasites are to be considered under seven families 

 having marked differences as to parasitic habit and also as to degree 

 of injury which they cause in their hosts. These are as follows : 



Family I. Ascaridse. 



Family II. Oxyuridse. 



Family III. Heterakidse. 



Family IV. Filariidse. 



Family V. StrongyUdse. 



Family VI. Eustrongylidse. 



Family VII. Trichinelhdse. 



Classification of Parasites of the Phylum Ccelhelminthes 



Phylum III. Ccelhelminthes. P. 216. 



Class A. Nemathelminthes. Smooth-bodied roundworms. P. 216. 

 Order 1. Nematoda. P. 217. 

 Family (a) Ascaridse. P. 229. 

 Genus and Species: 



Ascaris equi. Host, equines. P. 233. 

 Belascaris marginata. Host, dog, cat. P. 237. 

 Toxascaris limbata. Host, dog. P. 238. 

 Ascaris lumbricoides. Hosts, man, hog, sheep. P. 239. 

 A. vitulorum. Host, cattle. P. 241. 

 Family (b) Oxyuridse. Seat worms. P. 235. 

 Genus and Species: 



Oxyuris equi. Host, equines. P. 235. 

 Family (c) Heterakida. P. 242. 

 Genus and Species: 



Heterakis perspicillum. Host, poultry. P. 242. 

 H. vesicularis. Host, poultry. P. 242. 

 Family (d) Filariida. P. 244. 

 Genus and Species: 



Setaria labiato-papillosa. Host, equines. P. 244. 

 Habronema megastoma. Host, equines. P. 245. 

 H. microstoma. Host, equines. P. 246. 



