1. Department of Medicine and Epidemiology, School of Veterinary Medicine; University of California; Davis California
2. Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine; University of California; Davis California
3. Department of Veterinary Medicine; Universidade Federal do Parana; Curitiba, Paraná Brazil
4. Department of Population Health and Reproduction, School of Veterinary Medicine; University of California; Davis California
5. School of Veterinary Medicine; São Paulo State University; Araçatuba São Paulo Brazil