Affiliation: | a Virology Department, Veterinary Sciences Division, Department of Agriculture and Rural Development, Stoney Road, Belfast BT4 3SD, Northern Ireland, UK;b Department of Veterinary Biosciences, The College of Veterinary Medicine 1925 Coffey Road, Columbus, OH 43210, USA;c Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada |