Perilobular fibrosis in chronic bovine fascioliasis.

The character, extent, and localization of perilobular fibrosis were studied in cattle experimentally infected with Fasciola hepatica. Such fibrosis is indirectly due to the liver flukes. The regionally localized fibrosis results from cholestasis due to transient occlusion of branches of the biliary tree. In periobular fibrosis it is possible to distinguish a florid, an intermediate, and an uncomplicated form. The florid phase is marked by proliferation of the biliary epithelium and is followed by infiltration of inflammatory cells.