1. Departments of Veterinary Pathology
2. Cambridgeshire and Peterborough Public Health Network, Kingfisher House, Cambridgeshire, Huntingdon PE29 6FH, United Kingdom
3. Epidemiology Section, Animal Health Trust, Suffolk, Newmarket CB8 7UU, United Kingdom
4. Veterinary Clinical Sciences, University of Liverpool, Leahurst, Neston, Wirral CH64 7TE, United Kingdom
5. Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, United Kingdom