CHAPTER XXII 

 NEMATODA. SUBFAMILY II. TRICHOSTRONGYLINiE 



WOEMS OF THE StOMACH AND INTESTINE 



Strongylidse (p. 255). — These strongyles are parasitic only in the 

 ahmentary canal. The mouth is simple and without a buccal capsule 

 (Fig. 135). The body is generally straight or it may be somewhat 

 curved. The eggs are generally segmented at the time they are de- 

 posited. Development is direct, and infection, so far as known, is only 

 b}^ ingestion. 



Gastro-Intestinal Strongylosis of the Sheep and Goat 



1. Haemonchus contortus (Strongylus contortus). Fig. 134. 

 Trichostrongylinse (p. 268). — The body is filiform, attenuated at the 

 extremities, and red or white in color. The integument is striated 

 transversely. Near the anterior extremity there are two lateral tooth- 

 like papillae directed backward. The bursa of the male has two long 

 lobes and a small lobe accessory to the right (Fig. 136); there are two 

 spicules. The tail of the female is acutely pointed; anterior extremity 

 more gradually attenuated ; vulva toward posterior fifth of the bod^'. 



Length of female, 18-30 mm. (11/16-1 3/16 inches) ; male, 10-20 mm. 

 (3/8-3/4 of an inch). 



The eggs are elongated oval and measure 70-95 microns long by 

 43-54 microns wide. According to Railliet they contain developed 

 embryos at the time of deposition. Hatching probably takes place in 

 water, the embryo at the time of its release measuring 300-400 microns 

 in length by 17-21 microns in breadth. Infection is probably b}' drinking 

 water and contaminated pasturage bearing the larvae. 



The worm is parasitic in the abomasum and duodenum of sheep, 

 goats, and cattle. 



2. Cooperia curticei (Strongylus ventricosus; St. curticei). Fig. 

 137. Trichostrongylinse (p. 268).— The anterior end of the body is 

 usually coiled spirally. The cuticle at the region of the head is striated 

 transversely; cuticle of remainder of the body exhibits fourteen to six- 

 teen longitudinal lines. The mouth is small and not well defined. The 

 bursa of the male has two lateral lobes and a small median lobe. The 

 spicules are short. The vulva of the female is close to the posterior end 

 of the body. Tail slender and acutely pointed. « 



