1. Epidemiology Department; Centre for Preventive Medicine, Animal Health Trust; Lanwades Park, Kentford Newmarket Suffolk UK
2. Rossdales Equine Hospital; Cotton End Road, Exning Newmarket Suffolk UK
3. Royal (Dick) School of Veterinary Studies and The Roslin Institute, University of Edinburgh; Easter Bush Campus Roslin Midlothian UK
4. Veterinary Epidemiology; Economics and Public Health Group; Department of Production and Population Health; Royal Veterinary College; North Mymms Hatfield Hertfordshire UK