Pathomorphological changes, developing in case of pasalurosis chronic course in rabbits are described in the article. The research was held on ten rabbits of Large Grey breed, which were held on household farms of Poltava region. The diagnosing was complex: based on anamnesis data, clinical symptoms’ analysis, and the results of pathomorphological examination. The fragments of the liver, spleen, and kidneys were taken for histological analysis. While making histological analysis of the spleen it was revealed that lymphoid nodules were enlarged, some of them were of uniform structure, and others were in the state of hyperplasia. Non-uniformity of structure in addition to changing the size was registered in those nodules: there was less concentration of lymphoid cells in their central part and more concentration on the periphery. The situation was contrary in separate lymphoid nodules. The red pulp consisted of a large number of lymphoid cells and erythrocytes, the largest number of which were registered in the zones adjoining the places of lymphoid nodules’ location. Sometimes there were megakaryocytes in the field of vision. It was established, that blood filling of arteries was less than normal. In case of using some preparations, bilirubin inclusions were found at having big enlargements in red pulp. Grainy and fatty hepatocytes’ dystrophies, and also lymphohistiocytic interstitial hepatitis were also registered. At the same time, renal corpuscles were enlarged. Rather big spaces, filled with transparent substance containing vessel and cellular fragments (detritus), were revealed in the majority of them between glomeruli and the capsule.Capsule epithelial cells were destroyed in some places. Petechial hemorrhages were registered inside glomeruli. The destruction of separate podocytes and deep cells was noticed. The tubular epithelial cells were enlarged in size, and in some cases they were of cylinder, but not cubic shape; the spaces of such tubular were becoming correspondingly less. The epithelial cell cytoplasm of the tubular in some cases was not uniformand it was of cloudy-grey color: in other cases it had rather large colorless areas and, probably, looked like lipid inclusions (which were washed out from the cells as a result solvent impact during making histological preparations). Concentrations of eosinophilic masses (protein cylinders) sometimes containing certain amount of erythrocytes were often found in canaliculi spaces. Sometimes the destruction of epithelial cells was registered in the tubulеs, and their fragments were found in spaces. As a result of histological examination, the diffuse lymphohistiocytic infiltration in the renal interstitial tissue was found.