TRICHOSTRONGYLIN^ 275 



just beliind the vulva. The tip of the tail is truncate and bears a short 

 bristle-like process. 



Length of femal?, 10-24 mm. (3/8-15/16 of an inch) ; male, 8-13 mm. 

 (5/16-1/2 of an inch). 



The eggs are elongated oval, 110-113 microns in length by 64-70 

 microns in breadth; segmented at time of deposition. The further 

 development is not known. 



The worm is parasitic in the small intestine of cattle, sheep, and goats. 



3. Cooperia oncophora (Strongylus oncophora). Fig. 144. Tricho- 

 strongylinse (p. 268). — The head is rounded, without well-marked papil- 

 lae; mouth cavity small and not well defined. The cuticle in the region of 

 the head is transversely striated; cuticle of remainder of body with 14- 

 16 longitudinal Unes or ridges; cervical papillae absent. The bursa of 

 the male, when spread, is large and has two lateral lobes and a small 

 median lobe; border of median lobe incised. The spicules are short 

 and of comparatively simple structure. The vulva of the female is in 

 the posterior fourth of the body. At the region of the vulva the body is 

 much enlarged. The tail is slender with rounded tip; terminal portion 

 of tail marked with annular striations. 



Length of female, 6-8 mm. (5/16 of an inch) ; male about the same. 



The eggs are oval, 60-80 microns in length by 30 microns in width. 



Inhabits the small intestine of cattle and sheep. 



Occurrence and Sjnmptoms. — Hsemonchus contortus is frequently 

 found in the abomasum of cattle. When the infestation is heavy, which 

 usually occurs in young pastured animals, they bring about the symp- 

 toms of a pernicious anaemia as described in the infestation of sheep. 

 The cattle become infected by grazing upon pastures which are contam- 

 inated by the droppings of infected sheep, goats, or other infested cattle. 



The symptoms caused by the presence of Ostertagia ostertagi, or the 

 encysted stomach worm, are similar to those produced by Hcemonchus 

 contortus. It lives in small cysts in the mucosa of the abomasum and 

 is also found free in the contents of this organ. When numerous, they 

 cause a catarrhal condition and disturbances of digestion. 



For Post-mortem Appearance, Development, Etiology, Control, and 

 Treatment refer to pp. 275-279. 



Gastro-Intestinal Stbongylosis. Post-Mortem Appearance 



Examination of the contents of the abomasum and duodenum from 

 an animal which has been heavily infested with stomach strongyles 

 will reveal undulating movements of the fluid produced by the active 

 wriggling about of the worms. Large numbers will also be found deeply 

 adhering to the mucosa which will show the lesions of a subacute or 

 chronic catarrh. Further than this, the pernicious anaemia is evidenced 



