1 Department of Veterinary Medicine and Animal Productions, University "Federico II" of Naples, Via Veterinaria, 1, 80137 Naples, Italy. Electronic address: lucianna.maruccio@unina.it.
2 Department of Veterinary Medicine and Animal Productions, University "Federico II" of Naples, Via Veterinaria, 1, 80137 Naples, Italy.
3 Dpt. Normal and Pathological Morphology, University of Agricultural Science and Veterinary Medicine, 'Ion Ionescu de la Brad' Iasi Faculty of Veterinary Medicine, 8 M. Sadoveanu Alley, 700489 Iasi, Romania.