1. Veterinary practitioner, Enna, Italy
2. Department of Life Sciences and Systems Biology, University of Turin, Torino, Italy
3. Department of Veterinary Sciences, University of Torino, Torino, Italy
4. Veterinary practitioner, Palermo, Italy
5. Istituto Zooprofilattico Sperimentale della Sicilia “A. Mirri,” Barcellona P.G. (Messina), Italy
6. Azienda Sanitaria Provinciale Palermo, Palermo, Italy
7. National Research Council, Institute of Science of Food Production, Largo P. Braccini 2, Grugliasco, (TO), Italy