1. Department of Large Animal Internal Medicine; Faculty of Veterinary Medicine; Ghent University; Merelbeke 9820 Belgium
2. Clinic for Equine Internal Medicine; Vetsuisse Faculty; University of Zurich; Zurich 8057 Switzerland
3. Department of Veterinary Clinical Sciences; The Ohio State University; Columbus OH 43210
4. Department of Clinical Studies; New Bolton Center; School of Veterinary Medicine; University of Pennsylvania; Kennett Square PA 19348