Diseases of the Liver. 289 



flukes, inhabiting Uie bile ducts and reproducing them- 

 selves only by eggs. The necessity for these intermediate 

 generations, and the fact that they can only take place in 

 fresh water and in fresh water mollusks, points to thorough 

 drainage as the most ef&cient means of Hmitiug the ravages 

 of the parasites. 



In small numbers they do little harm and as they can- 

 not multiply withia the body their presence may be of no 

 consequence, but when present in large numbers they be- 

 come most destructive. In certain damp lands stocked 

 with these parasites sheep cannot live, no matter how 

 well fed, and cattle often perish as well. A single in- 

 fested sheep brought on such damp lands wUl speedily 

 stock them, as infested German rams did the colony of 

 Victoria in 1855. 



Symptoms. Sheep may thrive unusually for a month or 

 two, but soon they begin to lose flesh and waste with 

 a rapidity that is surprising. The skin and the membranes 

 of the nose and eyes become soft and puffy, the naturally 

 bright pink vessels of the eye become yellowish, dark, or 

 even quite imperceptible, the whole eye assumes a yellow 

 tinge, the skin is pale, bloodless, deficient in yolk or oil, 

 diy and scurfy. The wool loses its brilliancy and comes 

 out easily when pulled. The muscles waste, the animal 

 is razor-backed, the hip-bones project, and the flank becomes 

 sunken, the belly pendent and the back drooped from 

 dropsical effusion. Similar effusions take place in the 

 chest beneath the abdomen and breast-bone and under 

 the lower jaw. The head is no longer carried erect, the 

 expression of the face is haggard and hopeless, the appe- 

 tite capricious, thirst ardent, and there is occasional 

 diarrhoea. Examination of the dung detects myriads of 

 microscopic eggs -ywtt ^ch. in diameter. 



Treatment. Almost all the tonics of the pharmacopoeia 

 have been employed with more or loss effect, but aU usu- 

 ally fail when many parasites have gained access to the 



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