1. Equine Department; Division of Anaesthesiology; Vetsuisse Faculty University of Zurich; Zurich Switzerland
2. Department of Surgery, Anaesthesiology and Radiology; Faculty of Veterinary Medicine; Mansoura University; Mansoura Egypt
3. Institute of Physiology; University of Zurich; Zurich Switzerland
4. Equine Department; Division of Surgery; Vetsuisse Faculty University of Zurich; Zurich Switzerland