1. Pathobiology & Population Science, Royal Veterinary College, 4 Royal St, London, NW1 0TU, UK
2. Statistical Science Department, UCL, 1-19 Torrington Place, London, WC1E 7HB, UK
3. Department of Clinical Sciences & Services, Royal Veterinary College, University of London, Hatfield, UK
4. Department of Comparative Biomedical Sciences, Royal Veterinary College, University of London, Hatfield, AL9 7TA, UK
5. Department of Drug Design & Pharmacology, Faculty of Health & Medical Sciences, University of Copenhagen, Jagtvej 162, Copenhagen, DK-2100, Denmark
6. Department of Veterinary & Animal Sciences, Faculty of Health & Medical Sciences, University of Copenhagen, Stigbøjlen 4, Frederiksberg C, 1870, Denmark