348 The Diseases of Animals 



placed on the rump, and held between the knees, while 

 the medicine is slowly given ; if it is offered while the 

 animal is in a standing position, with the head raised, 

 the patient is unable to swallow. When strangled or 

 choked by oily medicines, animals stagger or fall, as if 

 intoxicated, "gagging," coughing, and breathing with 

 great difficulty. They may die from suffocation, or 

 from pneumonia, which is liable to follow choking. 



STOMACH -WORM OF SHEEP * 



In some of the central states, serious -losses among 

 lambs result from the invasion of the fourth stomach, or 

 abomasum, by a parasite, commonly called the "twisted 

 strongyle" (Hcemanchus contortus). It is most frequent 

 in wet seasons, and on low, marshy pastures; but after 

 the locality is once well infested the disease will be 

 found on high pastures, in those regions where there is 

 abundant rainfall and the air is moist. 



The life -history of the parasite is not well known. 

 The eggs are passed with the dung, and hatch after 

 falling in moist places. In this manner, probably, they 

 come to infest pastures and drinking places. It is 

 rare that sheep confined in barns and similar dry 

 places become infested. 



The disease usually affects young lambs, although 

 adult sheep may suffer with it occasionally. Old sheep 

 are likely to resist the disease. The animal falls away 

 in flesh, becomes weak and debilitated, and has a dull, 

 dejected appearance. It eats but little, and shows a 



* See an excellent account in Bulletin No. 117, Ohio Expt. Station. 



