120 



from which it was expected to secure specimens for illustration, only 

 a small piece of the worm was found, all the rest having passed away. 



Occurrence of the disease. — The worm, though present throughout the 

 year, is more abundant in the locality of Washington during May and 

 June than at an;s^ other season. This fact was doubtless somewhat de- 

 pendent on the age of the lambs examined, which were about three or 

 four months old at that time. In Colorado an outbreak was heard ol 

 in a flock of Merinos which occurred annually about July and August, 

 after which time the lambs would improve. The disease is more prev- 

 alent in the summer season, and causes the greatest damage in lambs 

 less than six months old. If the young animals cm be carried beyond 

 this age they seem to be either better able to withstand the ravages of 

 the parasite, or to have reached a season unfavorable for its develop- 

 ment. 



Duration. — The broad tape-worms do not last long in their adult state, 

 but after maturing nearly all their segments are shed at once. From 

 the time that the segments are shed the afflicted lambs will begin to 

 receive and rapidly lay on fat. The disease leaves no traces other than 

 debility in the early stages of recovery. 



Preventive treatment. — Treatment for the prevention of this disease is 

 that suggested for general prevention of parasites and an observance 

 of those measures which iiromote good health in the flock. Do not 

 overstock pastures. Give good, pure water. When possible, put the 

 lambs on new pastures. Feed some grain, put salt where the animals 

 can take it daily, feed hay from racks, and grains, salt, and water from 

 tioughs. 



The medical treatment j^romises better results than that for Tccnia 

 Jiinbriata, since the T. expansa is never lound wedged into the gall duct 

 or jiancreatic duct, as is T. fimhriata, but is found lower down in the 

 ymall intestine, from whence it can be removed. Many of the ])opular 

 tape- worm remedies are said to be eflticacious, but as the disease is dif- 

 ficult to diagnose until the worms begin to shed their segments much 

 damage is done to the health of the lambs before treatment begins. On 

 those farms and ranches where it appears periodically the lambs should 

 be treated as soon as they begin to show symptoms. Even then com- 

 plete cure can not be attained, for tiie lambs will continue to pick up 

 eggs as in the first instance. For safety all sheep in the flock should 

 be dosed, especially if all are to occupy the same pastures as those 

 affected. 



Ziirn {Die Schmarotzer, etc., p. 191, 1882), says that treatment is 

 practical when the disease is recognized before the lambs and yearlings 

 are reduced to a cachectic condition. Although those far reduced in 

 strength may not survive a medication, still they should be dosed in 

 order that the parasites may be expelled. Otherwise the sick not L,reated 

 should be yarded by themselves or killed and buried, so that they may 

 not scatter eggs for further infection. Before giving the sheep any 



