The hearts of 235 white sturgeons originating from an intensive farm s
ystem were examined in detail. Skin, muscle and abdominal viscera did
not show any pathological features, except for the presence of liver a
nd epicardial fat. All sturgeons had high levels of epicardial fat and
70% showed important variations in colouration, which was from grey/b
rownish to blackish. Histopathological examination revealed lymphocyte
infiltrates, around the blood vessels as small focal lesions near the
intercellular spaces, or as thin strips along the borders of fat tiss
ue. In severe cases, heavy lymphoid infiltrates and proliferative lesi
ons were evident and fatty tissue was replaced by inflammatory and pro
liferative tissue. The underlying myocardium was rarely affected. A di
agnosis of infiltrative and proliferative steatitis is postulated. Mor
eover, a high percentage of the livers showed steatosis. Aetiology is
still unknown, but the authors envisage a nutritional imbalance Linked
with oxidised fat intake. (C) 1997 Elsevier Science B.V.