PATHOLOGY OF ATLANTIC SALMON SALMO-SALAR INTRAPERITONEALLY IMMUNIZED WITH OIL-ADJUVANTED VACCINE - A CASE-REPORT

Gross and histopathological lesions in farmed Atlantic salmon Salmo sa lar L. immunized by intraperitoneal injections of oil-adjuvanted vacci nes are reported. A few fish farms report serious side effects leading to poor feed uptake and conversion, retarded growth and downgrading a t slaughtering due to severe adhesions between abdominal organs and bo dy wall. The lesions consist of granulomatous tissue adhering to and e mbedding different visceral organs in such a way that normal functions may become severely affected. Histologically, the tissue is character ized by granulomas embedded in a fibrous granulation tissue with high numbers of eosinophilic granule cells. Possible explanations for the o ccurrence of severe lesions at some farms are discussed.