1. Section of Anesthesiology, Equine Department; Vetsuisse Faculty of the University of Zurich; Zurich; Switzerland
2. Center for Microscopy and Image Analysis; University of Zurich; Zurich; Switzerland
3. Department of Anesthesia; University Children's Hospital Zurich; Zurich; Switzerland
4. Section of Epidemiology; Vetsuisse Faculty of the University of Zurich; Zurich; Switzerland