1. Department of Veterinary Public Health, Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Trau Quy, Gia Lam, Hanoi 12406, Vietnam
2. Maine Food and Agriculture Center, University of Maine Cooperative Extension, Orono, ME 04473, USA
3. G.A. Flory Consulting, Mt. Crawford, VA 22841, USA
4. Department of Anatomy and Histology, Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Trau Quy, Gia Lam, Hanoi 12406, Vietnam
5. Faculty of Veterinary Medicine, Vietnam National Univeristy of Agriculture, Trau Quy, Gia Lam, Hanoi 12406, Vietnam
6. Department of Pathoglogy, Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Trau Quy, Gia Lam, Hanoi 12406, Vietnam
7. Department of Animal Science, Michigan State University Cooperative Extension, Lansing, MI 48824, USA
8. Center for Epidemiology and Animal Health, Veterinary Service, U.S. Department of Agriculture, Animal and Plant Health Inspection Services, Fort Collins, CO 80521, USA
9. U.S. Department of Agriculture, Animal and Plant Health Inspection Services, Fort Collins, CO 80521, USA
10. Department of Statistics, Colorado State University, Fort Collins, CO 80523, USA
11. English Department, Johns Hopkins University, Baltimore, MD 21218, USA