550 Distomatosis. 



liver tissue probably die or they may make their way back into 

 the bile ducts, where they may become mature with those that 

 have remained there. A chronic inflammation associated with 

 the production of fibrous tissue is set up in the walls of the bile 

 ducts. At a later stage this inflammation spreads to the inter- 

 lobular connective tissue and results in cirrhosis of the liver. 

 The destruction of liver tissue following the migrations of 

 parasites also plays some part in the production of cirrhosis. 

 The toxic products of the metabolism of the parasites not only 

 cause irritation of the walls of the bile ducts, but also act upon 

 the liver tissue after absorption into the lymph stream. 

 Bacteria must also be taken into consideration in the produc- 

 tion of cholangitis. These may either be carried out of the 

 intestine by the flukes or they may be circulating in the blood 

 and, reaching the liver, find conditions suitable for multiplica- 

 tion in the diseased walls of the bile ducts. 



Jiiger 's investigations have sliown that the absorption of tlie toxic material 

 produced by the fluke is followed by a cellular infiltration in the angles between 

 adjacent lobules. This in its turn is followed by a production of connective tissue 

 and an extension of the process along the interlobular septa. As shown by Schaper 

 an active proliferation takes place in the bile ducts by a process of budding. 



The diffuse lesions of the liver tissue, the toxic metabolism 

 products of the flukes and the bacterial infection cause disturb- 

 ances of nutrition and of the process of blood formation. The 

 susceptibility of animals affected with liver rot to specific in- 

 fectious diseases may be increased (see hemorrhagic septice- 

 mia in Vol I). 



Carre and Bigoteau quite wrongly affirm that the sjanptoms of hydremia 

 in cases of distomatosis are due to an intoxication brought about by the multipli- 

 cation in some part of the body of the bacillus of pseudo-tuberculosis of Preisz and 

 Guinard. 



Anatomical Changes. If the invasion is extensive the liver 

 shows evidence of an acute inflammation (Hepatitis acuta trau- 

 matica distomatosa). The liver is enlarged, hjToeremic, its 

 serous membrane is studded with small hemorrhages, and may 

 be covered with a thin fibrinous deposit. The capsule shows here 

 and there small, round, sharpl3^-defined openings through which 

 a dirty red liquid exudes on pressure, and sometimes the an- 

 terior extremity of a fluke may appear. These openings lead 

 into irregular cavities in the liver tissue which contain blood, 

 liver debris and numbers of young flukes embedded in a pulpy 

 mass. If the liver be cut into, similar cavities are found in 

 other parts. The large bile ducts are dilated and contain large 

 quantities of muco-sanguinous bile and flukes in varying num- 

 bers. Exceptionally parasites escape into the peritoneum and 

 set up a severe peritonitis, or there may be severe hemorrhage 

 from the punctures caused by their escape. 



In less severe cases of chronic distomatosis the liver may 



