The first report of otarine herpesvirus-1-associated urogenital carcinoma in a South American fur seal (Arctocephalus australis).

Otarine herpesvirus (OtHV)-1-associated urogenital carcinoma has been well documented in the California sea lion (Zalophus californianus, CSL), but this is the first report of this tumour in a captive South American fur seal (Arctocephalus australis, SAFS). The gross and microscopical morphology of the tumour in the SAFS was identical to that described previously in CSLs and the tumour in the present case had metastasized within the urogenital tract and draining lymph nodes and to the lungs and one kidney. Immunohistochemistry revealed intra- and extracytoplasmic labelling of herpesvirus antigen in the cells of the tumour tissue and transitional epithelium of the urethra. OtHV-1 nucleic acids were detected within tumour tissue and from a urogenital swab by polymerase chain reaction. The ranges of these two species of pinniped do not overlap normally in the wild, suggesting that transmission of OtHV-1 probably occurred in captivity. This confirmed susceptibility of the SAFS to the development of OtHV-1-associated urogenital carcinoma suggests that all species of Otariidae should be screened for OtHV-1 infection prior to movement within and between zoological collections.