[Pathomorphological studies of experimental echinococcosis in sheep]

Histopathologic investigations in dynamic (from the 3rd up to the 15th month of infection) were carried out on echinococcus cysts and viscera (liver, lungs, spleen, and respective lymph nodes) of sheep with an experimental infection of Echinococcus granulosus. The echinococcus cysts differed in their development. Some of them showed normal structure, while others were in various stages of degeneration or full organization with calcification. The connective tissue capsule showed its characteristic layer structure. The liver presented strong destructive changes, particularly in tissue surrounding cysts in the stage of development. In the lungs there were interstitial and inflammatory changes with obturation of bronchioli (occasional findings). The organs of the peripheral immune system manifested morphologic changes that pointed to the presence of an immune response of mixed type.