1. Department of Veterinary Clinical Science; Anaesthesiology and Pain Therapy Division; Vetsuisse-Faculty; University of Berne; Länggasstrasse n.124 Berne CH-3012 Switzerland
2. Zoof Basel; Binningerstrasse 40 Basel CH-4054 Switzerland
3. F.Hoffmann-La Roche AG, Grenzacherstrasse 124 Basel CH-4070 Switzerland