1. Department of Veterinary Medical Sciences, University of Bologna, Ozzano dell'Emilia, Italy;
2. Department of Veterinary Neurology, The Animal Health Trust, Newmarket, Suffolk, UK;
3. Dick White Referrals, Six Mile Bottom, Cambridgeshire, UK;
4. Policlinico Veterinario Roma Sud, Rome, Italy;
5. Clinica Veterinaria Valdinievole, Monsummano Terme, Italy