SUMMER CARE AND MANAGEMENT 177 



lambs are born the sooner they will be gone to mar- 

 ket, and thus the fewer pastures will be needed. 

 Also the market is usually best in June and July, 

 after the flood of fed lambs has passed and before 

 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 nod- 

 ules 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 stom- 

 ach worm. The worm causing these tumors is 

 called oesophagostoma columbianum. 



This nodular disease is a hard one to cure, if in- 

 deed it is possible to cure it at all after it is estab- 

 lished. Prevention is about all that we can do. Dr. 

 W. H. Dalrymple of the Louisiana Experiment Sta- 

 tion has shown, however, that it is readily commu- 

 nicable 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 



