304 SUMMER MANAGEMENT 



intestine until it is swallowed by a grazing animal is unknown. The 

 parasite is beyond the reach of drugs while it is encysted in the walls 

 of the intestines. 



The effects of an attack of nodule disease are not immediate, 

 since it takes some time for the knotty concretions to develop. Nor 

 is the attack often fatal in the north central and eastern states. But 

 deaths frequently result from the Cfisease in the southern states. Its 

 effects are most injurious when combined with those of other diseases 

 such as stomach worm or tape- worm (Fig, 193). 



FIG. 193. Nodule disease. Note the knots or nodules that have been caused by the 

 parasites. (From Louisiana Experiment Station Bulletin 143.) 



If one has a flock badly infested with nodule disease he can 

 secure a crop of lambs free from it by raising them in a lot entirely 

 free from vegetation. 



Tape-worms are of six types. They are found in sheep in 

 nearly all parts of the world. In the United States it is somewhat 

 more common in the western than in the central and eastern parts, 

 where stomach worms are worse. In the adult stage, it inhabits 

 the small intestine, and since it develops great length of body (sev- 

 eral feet), it is needless to say that it is a greedy feeder and that it 

 saps the vitality of the host. The symptoms of tape-worm are very 

 much the same as those of stomach worm, except that the infested 



