1. Wildlife Health Center, School of Veterinary Medicine, University of California, Davis, California 95616, USA
2. Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, California 95616, USA
3. Marine Wildlife Veterinary Care and Research Center, California Department of Fish and Game, 1451 Shaffer Road, Santa Cruz, California 95060, USA
4. Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, California 95616, USA