1. Centre for Veterinary Epidemiology and Risk Analysis, UCD Agriculture, Food Science and Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland
2. Department of Agriculture, Fisheries and Food, District Veterinary Office, Poplar House, Poplar Square, Naas, Co. Kildare, Ireland
3. Irish Equine Centre, Johnstown, Naas, Co. Kildare, Ireland