204 COMMON DISEASES. 



their life history, are walled up in these nodules and beyond the 

 reach of any medical agent. 



It is possible that worm-destroving medicines, frequently re- 

 peated during the summer, might prove both curative and pre- 

 ventive, by killing the adult v^^orms, which live free in the intes- 

 tine. In dealing with a serious outbreak of this disease it should 

 be remembered that infested flocks usually do fairly well during 

 the summer and early fall months. If a flock is badly infested 

 with nodule disease it will generally prove good management to 

 nurse the flock through until spring, then depend on getting the 

 sheep into shape for market during the summer and sell out for 

 butcher stock in the early fall. Such sheep are entirely fit for food 

 purposes when in good flesh. 



Prevention. — New sheep should be purchased from a flock 

 that has been thrifty during two previous late winters and early 

 springs, and they should be kept for two seasons on some other 

 pasture than the one previously used on the infected farm. It will 

 be better still if the flock can be kept part of the season on pasture 

 and part of the seasons on plowed crops, e. g., rape, sorghum, 

 field peas, or meadow land that has not recently been used for 

 sheep pasture. The new flock must not be allowed to drink from 

 any pond or sluggish stream that has received drainage from the 

 infested pasture or barn yard. 



With a view to preventing this and other parasitic diseases, 

 the flock should not be kept too long on one pasture, but should be 

 moved from pasture to pasture ; and from pasture to stubble fields, 

 cut-over meadow, rape, etc. Sluggish streams and ponds should 

 be regarded with suspicion always. 



It is possible to practically rid a flock from this disease by 

 following this course of shifting the flock about for several years, 

 plowing up pastures occasionally and using plowed crops, but in 

 most cases, with the exception of valuable sheep, particularly 

 breeding flocks, it will usually be found more satisfactory to 

 change the entire flock on the plan suggested. 



