Hemorrhages in the base of the abdomen in trout: It is frequent to find this type of lesions in fingerlings, between 1 and 3 months old, together with skin discoloration, growth retardation and high mortalities. This clinical picture is compatible with IPN (infectious pancreatic necrosis) and IHN (infectious hematopoietic necrosis). These two viral diseases have a big impact on trout industrial farming because of the high mortality rates they cause.