282 Sheep-Farming 



they multiply within the sheep. The nodular dis- 

 ease is due to the invasion of the wall of the intestine 

 by the embryo of a worm that in its adult form lives 

 in the passage of the intestine. It may be possible 

 by the persistent use of worm medicine to dislodge 

 the mature worm, but nothing can be done to remove 

 the nodules. This, as other of the intestinal worms, 

 is communicated from one sheep to another through 

 the mediimi of the pastures. As the little lambs 

 begin to graze after their mothers, they pick up the 

 eggs, or young, expelled in the excrement of the old 

 sheep. Unless it is established that these parasites 

 of the sheep live from year to year outside the sheep, 

 it will be comparatively easy to grow a flock free 

 from them by raising the lambs in the winter and 

 never allowing them to follow old sheep upon the 

 pastures. It is a safeguard to have cultivated crops, 

 as rape, rye, oats, and peas, and even new seedings 

 of timothy and clover, for the ewes and lambs. Fre- 

 quent changing of the flock from one field to another 

 is also a safeguard from infection of the lamb. Have 

 two pastures, or better three, for each flock and leave 

 them in each pasture but one week at a time. 



Medicinal preventives. — A very large number 

 of proprietary medicines has been offered flock- 

 owners as remedies for internal parasites. Doubt- 

 less each of them contains one or more vermifuges, 

 but they are usually mixed with so much other 

 material and are sold at such high prices, compared 



