Kidney Diseases:
Furunculosis
Agent Aeromonas salmonicida subspecies. salmonicida
Hosts Esp. salmonids, but also in other species.
Location Kidney interstitium (and most other organs!).
Type of lesion Multifocal necrosis and liquefaction around bacterial colonies.
Special features Few other bacterial diseases show anything similar to this.
Diagnosis Demonstration of characteristic bacterial colonies, immunohistochemistry, isolation of the agent. Differential diagnosis include other bacterial septicaemia.


Bacterial colony and necrosis of interstitial tissue.


Atlantic salmon affected by furunculosis. Note the
characteristic Gram negative bacterial colony (the
red stained area in the middle of the image).

A number of Gram negative bacterial colonies throughout
interstitial tissue of Atlantic salmon kidney.