138 ANIMAL PARASITES IN THE STOMACH 



(gr. v) given in repeated doses once daily has been recom- 

 mended for qplts. 



Prevention. — As a preventive measure filtering the drinking 

 water is advisable. 



Strongylus Contortus. — This is commonly known as the 

 twisted palisade-worm, and is the cause of the so-called 

 stomach-worm plague of the sheep. The life-cycle of this 

 parasite is not understood. Probably the embryos are taken 

 up on the pastures or perhaps in the sheepfold. The stomach- 

 worm plague which this parasite induces is a serious disease 

 of lambs in the spring or during wet summers. The condition 

 may become enzootic, causing great economic losses. 



Symptoms. — The symptoms in general are those of a 

 chronic gastro-intestinal catarrh leading to emaciation, 

 anemia, hydremia, and death. On postmortem the 

 abomasum of the infested sheep will be found to contain a 

 large number of the small, filiform, reddish parasites, 2 or 3' 

 cm. in length. As noted, picrate" of potash (gr. ij-viij) is 

 recommended. 



Strongylus Convolutus. — This parasite is found in young 

 cattle and calves, also in sheep. It occurs in the abomasum, 

 where, under the epithelial layer of the mucous membrane, 

 it forms gray, pin-head to pea-sized nodules which contain 

 the parasites. If present in large numbers they produce 

 symptoms of gastric disturbance leading to diarrhea, emacia- 

 tion, and cachectic hydremia. 



OEsophagostoma in the Intestines (Nodule Disease). — The 

 larvae of the cesophagostomum frequently produce disease, 

 especially among cattle and sheep. Inasmuch as the most 

 characteristic lesion on necropsy is the nodule produced by 

 the larvse, the name "nodule disease" has been given to this 

 disorder. The following oesophagostomas occur in domesti- 

 cated animals: 



(a) (Esophagostomum columbianum of the intestines 

 (American sheep). 



(b) (Esophagostomum radiatum in the intestines. 



(c) (Esophagostomum venulosum of European sheep and 

 goats. 



(d) (Esophagostomum dentatum of the intestines of swine. 



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