Otarine gammaherpesviruses (OtHV-1) has been associated with urogenital carcinoma in California sea lions (Zalophus californianus).1 Molecular identification of three unique herpesviruses among Steller sea lions (Eumetopias jubatus) at rookeries in Alaska has also been described.2 Another gammaherpesvirus, Otarine gammaherpesvirus 4 (OtHV4), has also been recently described in Northern fur seals.3 West Coast Marine Mammal Network responders documented the health of an adult male Steller sea lion in decline over an 8 day period. The animal was first reported hauled-out on a public beach in Port Angeles, WA on January 6, 2017. Appropriate signage was posted for the public and his condition continued to be monitored. Over the first 5 days the sea lion was seen coming and going from the water although spending most its time on shore. Its condition continued to decline and it was humanly euthanized on January 14th. Necropsy revealed poor body condition with a minimal blubber layer and no internal fat. Lungs were white with some emphysema, liver edges were white and hardened, and increased CNS fluid was in the brain case. Several 2 to 4 cm dark red lesions were present on the penis, and teeth were markedly worn into the pulp on all four canines. Based on dentition and other physical characteristics it was determined to be a geriatric animal. Histologic findings included severe interstitial fibrosis, acute bronchopneumonia, severe hepatic fibrosis with biliary hyperplasia, and carcinoma in situ of the penile mucous membrane. Samples of penile lesions were submitted to three different laboratories; all confirmed the presences of a gammaherpesvirus. Sequence confirmation confirmed the presence of a herpesvirus with 96% nucleotide similarity to the gammaherpesvirus OtHV4 and 94% nucleotide similarity to OtHV-1 for a fragment of the DNA polymerase gene. Polymerase Chain Reaction (PCR) testing for papillomavirus E1 gene and papillomavirus L1 gene was negative. Additional sequencing and other diagnostics are being pursued. This appears to be the first reported Otarine gammaherpesvirus in a Steller sea lion with penile carcinoma in situ.
Acknowledgements
This work was funded by grant from the National Oceanic and Atmospheric Administration (NOAA), National Marine Fisheries Service through the John H. Prescott Marine Mammal Rescue Assistance Grant Program. Thanks to the West Coast Marine Mammal Stranding Network especially Fiero Marine Life staff, their volunteers, and Casey Mclean of SR3.
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