1. Department of Population Health and Reproduction School of Veterinary Medicine University of California at Davis Davis CA USA
2. Department of Large Animal Clinical Sciences College of Veterinary Medicine University of Florida Gainesville FL USA
3. Department of Pathology, Microbiology and Immunology School of Veterinary Medicine University of California at Davis Davis CA USA
4. Hagyard Equine Medical Institute Lexington KY USA
5. Maxwell H. Gluck Equine Research Center Department of Veterinary Science University of Kentucky Lexington KY USA
6. Department of Clinical Sciences Colorado State University Fort Collins CO USA