Kidney pathology in non-obstructive urolithiasis in cattle.

The objectives of the present study were to investigate the gross and histopathological findings in non-obstructive urolithiasis. Pathological examinations were carried out on 102 cattle kidneys with non-obstructive urolithiasis. The common gross lesions were cyst formations in the kidney lobes, hyperaemia and haemorrhage. The weight of the stones differed from 0.02 to 237.44 g and the colour changed brown to white. The calculi had different shapes. At histopathological examination of the kidneys slight to severe mononuclear cell infiltrations were commonly observed. Haemorrhage and connective tissue proliferations were also seen. Neutrophil leucocyte infiltrations caused by pyelonephritis were observed in some cases and multiple stone formations were found in these cases. Widening of the Bowman's space was a common histopathological finding especially when the stones were big or the inflammatory reaction was severe. Calcium deposits and eosinophylic material were found in the medullary tubules and pelvis renalis lumens in some kidneys. Giant cell formations around the stone reactions were rarely observed. Hyperplasia of the pelvis renalis and tubulus epithelium was another finding which occurred seldom. Whereas sand-like material accumulation seen in urinary bladders in some cases, no obstruction was observed in the urinary canal in this study.