TRICHOSTRONGYLIX.E 275 



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

 bristle-like process. 



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

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



The eggs are elongated oval, 110-113 microns in length b}' 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- 

 strongylina' (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 transversel.y striated; cuticle of remainder of body with 14- 

 16 longitudinal lines 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 Symptoms. — Haemonchus contortus is frequently 

 found in the al)omasum of cattle. When the infestation is heav}', which 

 usually occiu's in young pastured animals, they bi'ing about the sjniip- 

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

 The cattle become infected ])y grazing upon pastures which are contam- 

 inated by the di'oppings of infected sheep, goats, or other infested cattle. 



The s\Tuptoms caused by the presence of Ostertagia ostertagi, or the 

 cncj^sted stomach worm, are similar to those produced Ijj" 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 digest-ion. 



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

 Treatment refer to pp. 275-279. 



Gastro-Intestixal Strongylosis. Post-AIortem 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 fluitl produced by the active 

 wriggling a})Out of the worms. Large num])ers will also be found deeply 

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

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



