ABSTRACT
Spring viremia of carp (SVC) is a subacute to chronic disease of subadult, cultured common carp. Species of fish naturally infected with SVC are the common carp, bighead carp, silver carp, and grass carp. Fish experimentally infected by cranial injection express similar behavior. External clinical signs include darker pigmentation, a pronounced enlargement of the abdominal area, exophthalmia, and a prolapsed and inflamed anus. Diagnosis of SVC is made by isolation of Rhabdovirus carpio from diseased fish in cell cultures where replication of the virus occurs between 10 and 30°C with 21°C being the optimum. The fathead minnow (FHM) and epithelioma papillosum of carp (EPC) cell lines, or primary ovary cells of carp, are susceptible to SVCV and yields of 108 pfu/ml can be obtained. Histopathological descriptions of SVC are limited, but R. D. Negele reported on the histopathology of experimentally infected carp fingerlings. The liver has edema, necrotic blood vessels, and focal necrosis in the parenchyma.
