1. Unit of Equine Studies, Faculty of Veterinary Medicine and Animal Husbandry, Swedish University of Agricultural Sciences, P.O. Box 7046, 750 07 Uppsala, Sweden
2. Sport Horse Science, 3145 Sandhill Road, Mason, MI 3145, USA
3. Department of Clinical Sciences, Faculty of Veterinary Medicine and Animal Husbandry, Swedish University of Agricultural Sciences, P.O. Box 7057, 750 07 Uppsala, Sweden
4. Equine Department, University of Zurich, Rämistrasse 71, 8006 Zurich, Switzerland
5. Department of Anatomy, Physiology and Biochemistry, Faculty of Veterinary Medicine and Animal Husbandry, Swedish University of Agricultural Sciences, P.O. Box 7011, 750 07 Uppsala, Sweden