1. Equine Clinic; Free University of Berlin; 14163 Berlin Germany
2. Pferdeklinik Bargteheide; 22941 Bargteheide Germany
3. University of Edinburgh, Royal (Dick) School of Veterinary Studies, Easter Bush Estate, Roslin, EH25 9RG; United Kingdom
4. Institute for Veterinary Epidemiology and Biostatistics; Free University of Berlin; 14163 Berlin Germany