1. Maxwell H. Gluck Equine Research; Department of Veterinary Science; University of Kentucky; Lexington KY 40512 USA
2. University of Kentucky Veterinary Diagnostic Laboratory; Lexington KY 40512 USA
3. VMRD (Veterinary Medical Research and Development) Inc.; Pullman WA 99163 USA
4. Department of Biostatistics; University of Kentucky; Lexington KY 40512 USA
5. Virus Research and Testing Group; Division of Drug Discovery Research; Korea Research Institute of Chemical Technology; Daejeon Korea
6. Department of Veterinary Diagnostic and Production Animal Medicine; College of Veterinary Medicine, Iowa State University; 1600 South 16th St Ames IA 50011 USA