[1] Univ Bern, Vetsuisse Fac, Dept Vet Clin Sci, Anaesthesiol & Pain Therapy Div, CH-3012 Bern, Switzerland
[2] Univ Bern, Vetsuisse Fac, Dept Vet Clin Sci, Div Surg, CH-3012 Bern, Switzerland
[3] Univ Perugia, Fac Vet Med, Surg & Radiodiagnost Div, I-06100 Perugia, Italy