1. Veterinary Medicine Teaching and Research Center, School of Veterinary Medicine, University of California Davis, Tulare, CA 93274, USA
2. Department of Animal Hygiene and Veterinary Management, Faculty of Veterinary Medicine, Benha University, Moshtohor 13736, Egypt
3. Department of Population Health and Reproduction, School of Veterinary Medicine, University of California Davis, Davis, CA 95616, USA
4. Cooperative Extension, Division of Agriculture and Natural Resources, University of California, Orland, CA 95963, USA
5. Department of Veterinary Pathology, Microbiology & Immunology, University of California Davis, Davis, CA 95616, USA