150 ANIMAL PARASITES IN THE STOMACH 



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. 



NEMATODES IN THE STOMACH OF THE HORSE. 



The Spiroptera megastoma form tumors in the pyloric 

 portion of the stomach varying in size from a hickory-nut 

 to a hen's egg. When the' tumor is incised the thin thread- 

 like worm appears. They sometimes induce gastritis and 

 colic. 



Diagnosis. — The diagnosis is only possible by finding the 

 eggs in the feces which is extremely difficult as the embryos 

 (0.6 to 0.7 mm. long) leave the egg in utero. 



The Spiroptera microstoma are found free in the stomach 

 contents although some of them may be attached to the 

 mucous membrane of the cardiac region. They produce 

 ulceration and induration of the mucous membranes and 

 occasionally mild colic symptoms occurring during feeding, 

 weakness and emaciation. 



Treatment. — According to some authorities spiroptera may 

 be expelled by disulphid of carbon or large doses of lysol. 



ROUND WORMS IN THE STOMACH OF THE OX. 



Occurrence. — Several varieties of round worms (genus 

 Strongylus) inhabit the abomasum of cattle. They usually 

 do harm but occasionally in run-down young cattle on 

 pasture they produce formidable symptoms in a number of 

 animals in a herd or community. 



Varieties. — Several varieties of these parasites have been 

 described. The following are the most important: 



Ascaris vitulorum, male 15 to 24 cm. long; female up tia 

 30 cm.; found in the abomasum of calves. 



Hsemonchus contortus, male 10 to 20 mm. long; female 

 18 to 30 mm. 



Ostertagia ostertagia, male 6.5 to 7.5 mm. long; female 



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