NODULAR DISEASE IN SHEEP 347 



bandry holds forth better prospects. It should be borne 

 in mind that the earlier the lambs are born the sooner 

 they will be gone to market, and thus the fewer pastures 

 will be needed. Also the market is usually best in June 

 and July, after a flood of fed lambs has passed and be- 

 fore the new crop from the ranges has started to come. 

 Besides the stomach worm there is the worm that makes 

 the nodular disease of the intestines. Any observant 

 man who has dissected a mature sheep has often noticed 

 on the small intestines little nodules or "knots." These 

 are really small tumors, filled with a greenish, cheesy 

 substance. They do not do much harm when they are 

 few in number but the trouble is a cumulative one and 

 the numbers of the nodules increase until after a time 

 digestion and absorption are much interfered with. Some- 

 times parts of the intestines become calcified; that is, so 

 impregnated with lime salts that they are almost like 

 stone. Death ensues in a longer or shorter time from 

 the nodular disease. It does not work quickly as does 

 the disease caused by the stomach worm. The worm 

 causing these tumors is called cesophagostoma columbi- 

 anum. 



Nodular disease is difficult to cure, if indeed it is pos- 

 sible to cure it at all after it is established. Prevention 

 is about all that one can do. Dr. W. H. Dalrymple of 

 the Louisiana station has shown, however, that it is read- 

 ily communicable from affected ewes to their lambs 

 through the medium of the pasture. He has also demon- 

 strated that where diseased ewes are kept confined to the 

 barn and their lambs allowed to run on clean pasture 

 not contaminated by the presence of any old sheep, the 



