PATHOLOGICAL MANIFESTATION OF YERSINIOSIS IN SMALL CATTLE

Abstract

The article presents original materials and research analysis data on the pathological signalment of yersiniosis in small cattle. The purpose of the work was to collect and evaluate the current information on the spectrum of pathological presentation of yersiniosis in small cattle caused by various -Yersinia pathogens – Y. enterocolitica and Y. pseudotuberculosis. The authors utilized methods of comparison and juxtaposition of available data, pathological findings and results of pathomorphological research. Based on received information we defined pathognomonic changes in small cattle animal bodies during intestinal yersiniosis and pseudotuberculosis. Pathological manifestation of intestinal yersiniosis in sheep was characterized by catarrhal-hemorrhagic abomasitis and enterocolitis; pulmonary hyperemia with small abscesses and necrosis, hemorrhages on the epicardium; granular and fatty degeneration, abscesses, rarely granulomas and liver necrosis; hyperemia, hyperplasia, abscesses and necrosis of the spleen, acute non-purulent glomerulonephritis, necrosis rarely nephrosclerosis of the kidneys; catarrhal-hemorrhagic endometritis in females; serous-catarrhal lymphadenitis of regional lymph nodes; serous arthritis, bursitis and tendovaginitis; serous-catarrhal pleurisy and peritonitis. In goats with intestinal yersiniosis, the pathological changes were mostly similar but with pronounced degenerative changes in the internal organs. The course was often fatal, without any previous symptoms. However, the number of cases among these animals is much lower, however it should be noted, that the total number of examined goats is much smaller as well. Histological changes included catarrhal inflammation of the intestine with hypersecretion of mucus in goblet cells, desquamation of the epithelium with destruction of villi, relief of mucous and muscular membranes thickened, villi and crypts shortened with smoothed boundaries. Many vessels of the submucosal layer presented areas of fibrinoid necrosis within the wall, individual vessels were sclerotic, stenotic and deformed. Catarrhal inflammation was more often registered in the large intestine, and diphtheroid foci with necrotic pathces were more often registered in the cecum and colon. In the kidneys – the phenomena of fibrinoid necrosis of vascular walls with perivascular infiltration, focal necrosis of the brain substance, diffuse sclerosis, cystic tubular enlargement. Lungs show signs of catarrhal bronchopneumonia and interstitial inflammation with some areas of local alveolar emphysema. The lesions of the uterine mucosa is characterized by granulocyte infiltration, vascular thrombosis, focal necrosis of the mucosa. The pathological presentation of pseudotuberculosis in small cattle is characterized by miliary and nodular encapsulated, layered caseous nodules without petrification in the mesenteric, bronchial and mediastinal lymph nodes; nodular purulent – necrotic foci in the lungs, liver and spleen; non-purulent pyelonephritis; ascites and brain and spinal cord injuries are less frequent. Histological changes in lymph nodes are represented by granulomas, formed as a result of pathogenic action of Y. pseudotuberculosis and characterized by central karyorrhexis, polymorphonuclear leukocytic infiltration, presence of histiocytes, epithelioid and sometimes giant cells. The liver lesions also show signs of profound degenerative changes and necrosis (karyorrhexis, karyolysis). Changes within the spleen are represented by follicle and reticular cell hyperplasia with separate neutrophilic granulocytes; in the kidneys – evidence of glomerular damage, as well as degeneration and desquamation of the tubular epithelium; in the lungs – signs of catarrhal bronchopneumonia and interstitial inflammation, in some areas – local alveolar emphysema.