Effect of high concentrations of onion slurry via diet and bath on histological structure of the liver of Clarias gariepinus. A shows severe vacuolar degeneration of hepatocytes (arrow) and congested central vein (arrow head). B shows severe vacuolar degeneration of hepatocytes (arrow) and necrotized liver parenchyma (arrow head). C shows severe vacuolar degeneration of hepatocytes (arrow) and mild congestion of blood vessels (arrow head).