DISEASES OF SHEEP 577 



brane. The thick portion or caudal extremity floats freely in the 

 intestinal contents. The life history is simple. The eggs, after 

 passing to the ground and developing to a certain extent, pass with 

 food or water into the intestine again, where they complete their de- 

 velopment. 



The caecum worm is not thought to be especially harmful, but 

 when present in large numbers alone or in conjunction with other 

 parasites, it may cause serious trouble. The usual worm remedies 

 can be used with a considerable degree of success. After the admin- 

 istration of oil of turpentine these worms are passed in considerable 

 numbers. 



THE FRINGED TAPEWORM OF SHEEP (THYSANOSOMA FIMBRIATA) . 



An adult worm measures from 6 to 12 in. in length. In com- 

 parison with other species of tapeworm the head is large, about the 

 size of a pin's head, and provided with four distinct suckers. For 

 the purpose of this report it is deemed neither advisable nor essential 

 to enter into a minute description of the structure of this parasite. 



The possession of one peculiar and characteristic feature per- 

 mits of the ready identification of the fringed tapeworm. The poste- 

 rior border of each segment of the worm bears a fringe, giving a 

 velvety appearance to the entire animal. If there is any doubt as 

 to the identification, the presence of this fringe can be readily rec- 

 ognized by placing the worm in a small vial of water, thus causing 

 the fringe to float out somewhat from the segments of the body. 



Distribution, Mortality and Occurrence. The tapeworm has 

 been found by Natterer in species of deer in South America. In 

 sheep it is reported from Colorado, Utah, Nebraska (Curtice) ; New 

 Mexico (Cadweiss, Curtice) ; California, Oregon, Utah (Curtice) ; 

 Missouri (Stewart, Curtice) ; Washington, D. C. [in sheep from Colo- 

 rado (Hassall and Stiles). 



Experience shows that even in the best cared for flocks the mor- 

 tality may run high, and there is truth in the statement of Curtice 

 that it forms- at times a veritable scourge to the sheep industry of 

 the western plains. 



In the majority of cases this tapeworm is found in the duode- 

 num or first portion of the small intestine. Not infrequently, how- 

 ever, they may be found in the common bile duct from the liver, and 

 also in some cases in the hepatic ducts. Curtice states sometimes 

 they may be found in the ducts of the pancreas, believing that they 

 enter these various channels while young. 



Life History. The exact life history of the fringed tapeworm 

 is unknown. Curtice's experiments in attempting to infest young 

 lambs directly with eggs from the fringed tapeworm proved nega- 

 tive, which suggests that, like many other tapeworms, it must pass 

 through some intermediate host or hosts. Yet this is merely con- 

 jecture and, as above stated, its life history has not been fully de- 

 termined. 



Symptoms. The attention of the owner is probably first at- 

 tracted to the disease by the fact that lambs which should be doing 

 well are unthrifty, scour and soon begin to gradually die. A more 



