[Differential pathomorphologic diagnosis of brucellosis in hares]

The examination comprised 656 cases of brucellosis, 208 cases of pseudotuberculosis, 31 cases of yersiniosis, 13 cases of tularemia and 120 cases of pasteurellosis. In brucellosis, changes in liver, spleen and sexual organs prevailed. The macroscopy of the changes was typical. A histiocytic granuloma of tuberculoid type was found by histological examination. Owing to caryolysis, the central necrosis of granulomata contained a conspicuously small amount of nuclear detritus, and big cells of Langhans type were found in the histiocytic layer. A layer of round-cell elements constantly occurred on the periphery of the necrosis and peripheral fibrotization was observed in older granulomata. Pyogenic component was almost absent. Pseudotuberculosis and yersiniosis were characterized by septic tumour of the spleen and alterations in liver, lungs, kidneys, and the terminal section of ileum. In pseudotuberculosis necrotic changes occurred in bone marrow and in processus vermiformis. The changes were histologically limited by the formation of granulomata and necrosis with characteristic karyorrhexis and with tht occurrence of masses of bacteria in the necroses. Neutrophiles were constantly found to be present in the changes, whereas peripheral fibrotization was not typical. In tularemia, besides spleen tumour, alterations in lungs prevailed, having a vitreously smoky appearance, bacon-like on cross section. From the histological point of view, a histiocytic granuloma of tuberculoid type was involved. Its only differences from brucellosis were the larger content of nuclear detritus owing to karyorrhexis and the occurrence of erythrocytes in the lung alterations where marked peribronchial and perivascular infiltrates were present. The typical location of spleen alterations was the periphery of Malpighian corpuscles. Staphylococcosis was differentiated by a purulent nature of the changes and pasteurellosis by a constant finding of pneumonias and tracheitis.