1Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy;2Department of Agricultural Sciences, University of Naples Federico II, Portici, Naples, Italy; 3Istituto Zooprofilattico Sperimentale del Mezzogiorno, Portici (Naples), Italy;4Azienda Sanitaria Locale Avellino (Ariano Irpino), Avellino, Italy.