CHAPTER XXII 



NEMATODA. SUBFAMILY II. TRICHOSTRONGYLIN.E 



Worms of the Stomach and Intestine 



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

 alimentary 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 onl.v 

 by ingestion. 



Gastro-Intestinal Strongylosis of the Sheep and Goat 



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

 Trichostrongyhnse (p. 268). — The body is fiUform, 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 gradualh'- attenuated; vulva toward posterior fifth of the body. 



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 300^00 microns 

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

 water and contaminated pasturage bearing the larvse. 



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

 goats, and cattle. 



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

 137. Trichostrongyhnse (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. 



