Pigmentations
Discolouration of the kidney has several possible causes and can be the result of either a serious or insignificant pathology.
- The release of haemoglobin following a haemolytic crisis can lead to black discolouration of the kidney. An example includes chronic copper poisoning in sheep.
- Haemosiderosis can be associated with haemolytic anaemia or residue from acute haemoglobinuria. Brown discolouration of the cortex occurs and haemoglobin can be seen histologically using Perls Prussian Blue reaction which stains Ferric iron blue.
- Melanin deposits can occur in the pelvis or parenchyma in pigmented breeds of all species. They are of no pathological significance.
- Radial dark brown lines in the cortex can occur in lipofuscinosis.
- Icterus due to hepatic failure can result in a green/yellow discolouration of the kidneys.