1 Royal (Dick) School of Veterinary Studies and The Roslin Institute, University of Edinburgh, Roslin, Midlothian EH25 9RG, email: richard.mellanby@ed.ac.uk.
2 School of Veterinary Sciences, University of Bristol, Langford House, Langford, Bristol BS40 5DU.
3 Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, 464 Bearsden Road, Glasgow G61 1QH.
4 Institute of Ageing and Chronic Disease, University of Liverpool, Leahurst Campus, Neston, Cheshire CH64 7TE.
5 School of Veterinary Medicine and Science, University of Nottingham Sutton Bonington Campus, Leicestershire LE12 5RD.
6 Department of Clinical Sciences and Services, Royal Veterinary College, Hawkshead Lane, North Mymms, Hertfordshire AL9 7TA.
7 UCD School of Veterinary Medicine, Veterinary Sciences Centre, Belfield, Dublin 4, Ireland.
8 Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES.
9 Edinburgh Clinical Academic Track Programme, College of Medicine and Veterinary Medicine, Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh EH16 4TJ.