NODULE DISEASE 303 



can be thoroughly churned together by working the piston of the 

 syringe. Then too, when drenching, the pressure from the piston 

 forces the liquid so far down the throat that the sheep or lamb does 

 not seem to notice the gasoline. This is an important point, for if 

 the animal is not excited and struggling when the dose is being 

 swallowed, it goes directly to the fourth stomach, where the worms 

 are located, but otherwise it is likely to go into the first stomach, or 

 paunch, where it will do practically no good. 



When to Drench. The whole flock should be drenched at wean- 

 ing time and again about ten days later. In case the infestation is 

 very bad, it may be necessary twice or three times more at intervals 

 of about thirty days. 



Prevention of Stomach Worms by Use of the Dry Lot. 

 There is one way in which it is possible to raise lambs so that they 

 will be practically free from stomach worms, even though their dams 

 are badly infested. That way is to raise them in the dry lot a lot 

 in which no plant is to be found growing. Such lambs have all the 

 manifestations of health and post mortems show them to te almost 

 free from infestation. Out of a number of stomachs examined, 22 

 was the largest number of worms found in any individual by 

 the writer, and this animal had a wool ball in its stomach. In 

 case of pure-bred flocks becoming heavily infested, it may be advisable 

 to raise a crop of lambs in the dry lot, for in so doing, clean, 

 vigorous breeding animals can be secured. Then, too, other un- 

 desirable internal parasites may be avoided at the same time. 



Nodule Disease. Nodule disease is due to a parasite ((Esoph* 

 agostomum columbianum) , the embryos of which form knots or con- 

 cretions inside both the large and small intestines. In the worst 

 cases these concretions are thickly studded on the intestine along its 

 entire course, and their harmful effects come from their interfer- 

 ence with the processes of digestion and absorption of food materials. 



The life history of the parasite which causes nodule disease is 

 not well known. It seems that the mature female lays her eggs in 

 the intestine, where they hatch in a short time, and in some manner 

 pass through the mucus lining of the bowel and become embedded 

 or encysted in the intestinal wall. As nearly as is known the irrita- 

 tion caused by the embryos give rise to the concretions. Dalrymple, 

 of the Louisiana Station, found that the parasite which causes 

 nodule disease is swallowed by the sheep while grazing; what hap- 

 pens to the parasite from the time it leaves the concretion in the 



