1. Research Center on Animal Pain, Department of Veterinary Medicine, University of Perugia, 06126 Perugia, Italy
2. Innovative Statistical Research SRL, 35123 Padova, Italy
3. Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, P.O. Box 66, 00014 Helsinki, Finland
4. CeDIS (Centro di Documentazione e Informazione Scientifica), Innovet Italia SRL, 35030 Saccolongo, Italy