ANIMAL PARASITES AND PARASITIC DISEASES 325 



Unless carefully handled, pigs and lambs may succumb to the 

 treatment. For this reason none but an experienced person 

 should attempt to administer the medicine. 



The stomach worm of sheep (Hamonchus contortus) is red or 

 white in color according to the amount of blood sucked into its 

 intestine from the mucous lining of the stomach of the host. The 

 male worm is from K to 1 inch in length and the female from 

 1 to 1 J^ inches. They inhabit the fourth stomach and appear as 

 myriads of short, hair-like bodies. Lambs infested with this 

 parasite fail to thrive, have little appetite, are dull, thirsty, weak, 

 and may scour. In bad cases the belly enlarges, the wool be- 

 comes harsh, the skin pale, and the lining of the eyelids white or 

 pale in color. At this stage the most characteristic symptom of 

 the trouble is the appearance of a dropsical swelling under the 

 jaw. Gasoline has given good results as a remedy. It is ad- 

 ministered to each well grown lamb in half ounce doses (one 

 tablespoonful) mixed in 6 ounces of milk, for three successive 

 mornings before feeding. Copper sulphate in 1 per cent, solu- 

 tion has been found to be very efficacious against stomach 

 worms in sheep. The dose is 100 c.c. for sheep a year old or. 

 older, and 50 c.c. for lambs under a year old. 



The nodular disease worm of sheep (CEsophagostomum co- 

 lumbianum') is a thread-like, round worm. It measures about 

 M^O/4: l QC h long and is found in the intestines. The eggs, which 

 are passed out with the feces, contaminate food and water and 

 are hatched outside the body. When the parasites are taken into 

 the host and reach the intestines they immediately penetrate the 

 bowel wall and there produce the characteristic nodules, about 

 the size of a pea, that are seen on the outer surface of the gut 

 and from which the disease gets its name. In badly infested 

 cases the mesentery, liver, and other surrounding organs may be 

 studded with the parasitic nodules. If a nodule is opened it is 

 found to contain a green, cheesy pus and usually the parasite. 

 The disease can be distinguished from tuberculosis by the fact 

 that neighboring lymph glands are not involved. Besides, tuber- 

 culosis is extremely rare in sheep, so there is little danger of con- 

 fusing the two. Injuries produced are according to the extent of 

 the infestation, vitality, and age of the sheep. If few worms are 

 present it is not especially serious. In large numbers the nodules 

 prevent the absorption of food material. 



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