STOMACH WORMS IN SHEEP: 



PREVENTION AND TREATMENT. 



CONTENTS. 



Page. 



How can one tell when sheep have stomach worms ? 3 



How do the worms injure the sheep ? 4 



How should infested sheep or lamhs be treated ? 4 



How do sheep become infested by stomach worms ? 6 



What methods can be employed to prevent loss from stomach worms ? 8 



ONE of the most serious problems of owners of farm sheep is the 

 prevention of injury and loss by stomach worms. This para- 

 site (Hxmonchus contortus) has been known in this country for many 

 years and is common in farm flocks, particularly during wet summers. 

 It has been studied bv the Zoological Division of the Bureau of 

 Animal Industry and the principal facts in its life history have been 

 determined. Methods of treatment and of prevention are still under 

 investigation by that division, and although the methods have not 

 yet been perfected, what has been learned is sufficient to show how 

 affected sheep or lambs can be treated successfully and, what is of 

 greater importance, how they may be raised in such a way as practi- 

 cally to overcome the danger. 



What is known of this parasite and the methods of prevention and 

 control may be presented as answers to practical questions, as 

 follows : 



HOW CAN ONE TELL WHEN SHEEP HAVE STOMACH WORMS? 



Either lambs or old sheep may be affected by stomach worms at 

 any time of the year. The trouble may be noticed first in lambs 

 about the middle of summer, though it may be earlier, according to 

 the part of the country and the temperature and moisture of the 

 season. 



In many flocks the first knowledge of the trouble is gained through 

 the death of one or more lambs. If the flock is under careful obser- 

 vation, however, signs of stomach-worm disease will be noticed 

 earlier. Dullness and lack of thrift are among the first indications. 

 Scouring is often present. These conditions may result from other 

 causes, but when due to stomach worms, they are accompanied with a 

 very pale, bloodless appearance of the skin and of the mucous mem- 

 branes of the eyes and mouth. The whiteness of the skin has caused 

 the trouble to be known in some sections as "paper skin." In many 

 cases there is a watery swelling under the jaws. 



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