1. Department of Veterinary Medicine, University of Perugia, Perugia, Italy;
2. CSCS-Centro di Studi del Cavallo Sportivo, University of Perugia, Perugia, Italy;
3. CeSDA-Centro di Studio sul Dolore Animale, University of Perugia, Perugia, Italy;
4. Department of Veterinary Sciences, University of Pisa, Pisa, Italy