Fig. 6

Histopathological lesions in smallmouth bass (Micropterus dolomieu) infected with the largemouth bass virus. a Focally extensive hepatocellular degeneration and necrosis (asterisk) with secondary infiltration of heterophils (arrowhead). b Liver with focal area of coagulative necrosis (asterisk) characterized by loss of nuclear detail and hypereosinophilia of affected hepatocytes surrounded by cellular debris and few infiltrating heterophils. c Focal splenic necrosis (asterisk) with lymphocytolysis and karyorhectic debris. d Spleen with confluent area of coagulative necrosis (asterisk). e Mesenteric fat with focally extensive necrotizing steatis (asterisk) adjacent to the intestinal wall. f Kidney with focal area of fibrinoid necrosis (asterisk) with loss renal tubules and replacement by accumulating fibrin admixed with cellular debris and macrophages. Fish in a, c, and e were infected by intraperitoneal injection, while fish in b, d, and f were infected by immersion