Author: John F. Prescott

Carlton L. Gyles, DVM, MSc, Ph D, is Professor of veterinary microbiology at Ontario Veterinary College, University of Guelph, Ontario, Canada. John F. Prescott, MA, Vet. MB, Ph D, is Professor of veterinary microbiology at Ontario Veterinary College, University of Guelph, Ontario, Canada. J. Glenn Songer, Ph D, is Professor of veterinary science and microbiology, University of Arizona, Tuscon, Arizona. Charles O. Thoen, DVM, Ph D, is Chair and Professor of microbiology, immunology, and preventive medicine, Iowa State University, Ames, Iowa.