ERADICATION OF STOMACH WORMS 299 



worms it is well to examine the animal shortly after death be- 

 fore it has become cold, if possible for otherwise the worms may 

 be dead and disintegrated beyond recognition. Before opening the 

 stomach, it should be placed so that a slit can be cut in it which 

 will permit of examining the liquids before they escape. If many 

 live worms are present, they can be seen wriggling in the liquids, 

 and are found on the inner wall of the stomach. 



How the Worm Does Harm. How does the stomach worm do 

 harm? By sucking blood from the mucus lining of the stomach. 

 It has a spear-like instrument called a buccal tooth, which it thrusts 

 into the blood-vessels and draws nourishment from the blood of 

 the host. After knowing the manner in which the worm lives, we 

 can easily understand why a sheep or lamb heavily infested may 

 have a pale skin, lusterless wool, very little blood in the veins of the 

 white of the eye, disordered digestion characterized by a depraved 

 appetite for dirt, or by scours. It is also easy to understand why 

 heavily-infested animals get so thin in flesh and why lambs' become 

 so weakened that they die. When any of the above symptoms appear, 

 an examination should be made to ascertain whether the worms are 

 present even if it involves killing one or two of the most suspected 

 animals. If an animal is heavily infested, hundreds of worms are 

 present. A hundred or less would of themselves check the well- 

 doing of a lamb but little, although the presence of such a number 

 is indicative of the possibility of gathering more from the pastures 

 on which the animal has been running. 



Eradication of Stomach Worms. Unfortunately, we have 

 not learned how totally to eradicate stomach worms from a flock 

 of sheep, nor have we learned how to handle pastures or other 

 growths from which sheep graze, so that we can feel sure they will 

 not pick up a new infestation. But we have learned how to hold 

 the infestation in check to such extent that except in occasional 

 instances, the flock will appear thirfty and the lambs will grow into 

 a choice product. 



Changing Pastures. Undoubtedly changing often to new graz- 

 ing grounds helps a great deal to check infestation. If it were pos- 

 sible to move to new pasture every ten days, the lambs would seldom, 

 if ever, have outward indications of stomach worms. Such a 

 method of handling may be impracticable for all except owners of 

 pure-bred flocks, but a rotation on three to five different grazing 

 grounds would help a great deal. On a well-fenced farm where 



