Int. J. Environ. Res. Public Health 2009, 6 2.2.2. Pathohistological examination 3132 Histological examination of the kidneys showed two types of changes: degenerative-affecting epithelial cells in some proximal tubules of pigs, and proliferative changes in the interstitium. The major renal histopathological changes were mainly in the epithelium of proximal tubules (Figures 2 and 3). Dystrophy (moderate to marked degenerative changes, Figure 2C), swelling, vacuolization and lipidosi, were the main changes in the tubular epithelial cells. The majority of glomeruli exhibited mild or moderate exudates in Bowman’s capsular spaces as well as hypercellularity of vascular loops. In addition vascular changes expresed as a hyperaemia of blood vessels, moderate to marked haemorrhages of some renal cortical regions occurred occasionally (Figures 2A and 3). In the interstitium of some renal cortical regions, there was limited proliferation of connective tissue (Figure 2D) and focal infiltration of mononuclear inflammatory cells which was sometimes accompanied by small granulomas. Figure 2. Major renal histopathological changes. Hemorrhages in cortex (A), Fatty change (B), Dystrophy and vacuolar degeneration in the epithelium of proximal tubules` cells (C), and Focal interstitial nephritis (D). A C B D