1. Department of Veterinary Anesthesiology, Faculty of Veterinary Medicine, Universidad Autónoma del Estado de México, Toluca, México
2. Department of Preventive Medicine and Animal Health, Faculty of Veterinary Medicine, Universidad Autonoma de Yucatan, Merida, México
3. Medical and Surgical Research Unit, Hospital Universitario Puerta de Hierro Majadahonda, Manuel de Falla 1, Madrid Spain
4. Department of Small Animal Clinical Seiences, School of Veterinary Medecine Rakuno Gakuen University, Ebetsu, Hokkaido Japan