298 DISEASES OF THE DIGESTIVE APPARATUS. 



biliary canals have ordinarily trebled or quadrupled in size ; in the 

 ox they may reach the diameter of the thumb, which gives the 

 liver a ^' vesiculous'^ or cystic appearance. In the dilated biliary 

 canals we find, with a red mucous bile, fluke- worms and their eggs 

 in more or less large quantities ; in the sheep's liver the number of 

 parasites may increase to one thousand. The mucous membrane 

 of the canals, which is constantly irritated by the stinging cuticula 

 of the large fluke-worms, becomes the seat of a hemorrhagic mucous 

 or purulent catarrh ; later on it is considerably thickened by a 

 connective tissue neoformation ; it may become incrusted with 

 phosphate of lime. The biliary canals are then transformed into 

 hard columns, which are very visible to the naked eye ; they are 

 often prominent upon the surface of the liver. At the same time 

 the hepatic parenchyma becomes more and more atrophied, hard, 

 and creaks under the sharp instrument ; its surface is irregularly 

 embossed (atrophy of the liver, cirrhosis). In the ramifications of 

 the portal system we may find thrombosis produced by fluke-worms 

 floating free within the bloodvessels. The gall-bladder contains, 

 as a rule, turbid and dirty bile, isolated fluke- worms, and eggs in 

 considerable quantity. 



At a more advanced phase of the disease we find almost always 

 ascites, with isolated fluke-worms in the peritoneum, as well as a 

 thickening of the pleura and pericardium. The carcasses are much 

 emaciated, the fat has entirely disappeared, the muscles are pale 

 and flabby ; the blood is thin and watery ; the connective tissue is 

 infiltrated with œdema (anemia and hydremia). 



Symptoms. The symptoms of distomiasis have nothing char- 

 acteristic ; at the start, and often during several weeks, there does 

 not exist any morbid manifestation ; after one or two months, 

 where the trouble has acquired a certain gravity, we observe 

 symptoms of cachexia, serious disturbances of nutrition, and 

 hydremia (the ^' sheep rot"); but all these phenomena are com- 

 mon to other diseases. The animals lose flesh very rapidly ; the 

 mucous membranes are pale, as if washed ; the wool is dry, dull, 

 and drops off very easily ; the eyelids, the larynx, and the belly 

 become œdematous. In the ox the hair appears dull and brittle, 

 the skin is dry and sticky. Gastric complications are added to 

 these symptoms. The appetite is capricious or wanting, rumination 

 is suspended, and constipation alternates with diarrhea ; the urine 

 becomes acid. The sick sheep are very weak, they remain behind 



