152 THE ANIMAL PARASITES OF MAN 



said to have been introduced into Australia in 1855 by imported 

 rams sent from Germany to Victoria. F. V. T.] 



The liver fluke, however, is by no means a harmless parasite, 

 for it produces in domestic animals, more especially in sheep, 

 a disease of the liver that appears epidemically in certain years 

 and districts, and commits great ravages amongst the flocks. 



[The following records show the enormous loss caused in sheep 

 by this parasite. In 1812, in the Midi, principally in the Depart- 

 ments of the Rhone, Herault, and Gard, the disease was rampant ; 

 300,000 sheep perished in the Aries territory, and 90,000 in the 

 arrondissements of Nimes and Montpellier. In 1829 and 1830, in 

 the Department of the Meusc and near localities, not only sheep 

 but oxen died in enormous numbers ; for instance, in the arron- 

 dissement of Verdun out of 50,000 sheep 20,000 died, and out of 

 20,000 cattle 2,200 died. In England, in 1830, 2,000,000 sheep 

 were carried off; whilst, in 1862, 60 per cent, of the sheep died in 

 Ireland ; and in 1879 over 300,000 were lost in England ; whilst as 

 late as 1891 one owner in the same country lost over 10,000 

 sheep (Live Stock Journal, October 30, 1891).- F. V. T.] 



The disease usually commences towards the end of summer 

 with an enlargement of the liver, induced by the invasion of 

 numerous young flukes ; in the autumn and winter the animals 

 suffer from the consequences of disordered biliary secretion ; they 

 become feverish, emaciated and ana-mic, and lose their appetite. 

 In consequence of the consecutive atrophy of the liver cedema 

 and ascites set in and many animals succumb to this " liver rot." 

 On examination the liver is found to be shrunken, the bile ducts 

 are enormously dilated, and in parts contain sacculations full of 

 hepatic flukes. Should the animals survive this stage, a spon- 

 taneous recovery ensues in consequence of the flukes commencing 

 to leave the liver in the spring, but the liver remains altered and 

 its sale is prohibited l when the changes are extensive. 2 



[The following stages may be noticed in sheep suffering from 

 distomatosis. Gerlach recognised four stages, based - on the varied 

 relations that the flukes contract with the liver of their host. 



1 [This is not the case in Great Britain ; Fluky sheep are sent to market ; there being 

 no danger to man eating the flesh. F. V. T.] 



2 As an example, this occurred in Berlin in the case of 19,034 oxen, 15,542 sheep, 

 i, 704 pigs, and 160 calves in the period of 1883-1893 ; during which time 719,157 oxen, 

 1,519,003 sheep, 2,258,110 pigs, and 567,964 calves were slaughtered. As a matter 

 of fact, however, the number of infected beasts was really larger. 



