Hepatitis B-like infection in a Pacific white-sided dolphin (Lagenorhynchus obliquidens)

A Pacific white-sided dolphin (Lagenorhynchus obliquidens) developed clinical signs, serum biochemical values, and serologic viral markers consistent with chronic persistent hepatitis caused by a hepatitis B-like virus. The hepatitis had a sporadic cyclical pattern of lethargy, inappetance, and icterus, with leukocytosis and increased serum activities of alanine transaminase, aspartate transaminase, and gamma-glutamyltransferase. The serum from this dolphin contained hepatitis B virus core antibodies, hepatitis B surface antibodies, and hepatitis B viral DNA. Supportive treatment consisted of administration of antibiotics, cimetidine, menadiol sodium diphosphate, and vitamin/dextrose supplementation. A clinically normal killer whale (Orcinus orca) housed in the same pool had serum hepatitis B surface antibodies, suggesting immunologic responsiveness and that this disease was not species-specific.