[1] UNIV PERUGIA,IST MALATTIE INFETT PROFILASSI & POLIZIA VET,I-06100 PERUGIA,ITALY
[2] UNIV PERUGIA,IST SEMEIOT MED & METODOL CLIN VET,I-06100 PERUGIA,ITALY
[3] IST ZOOPROFILATT SPERIMENTALE LOMBARDIA & EMILIA,BRESCIA,ITALY
[4] UNIV PERUGIA,IST TECN AUTOPSIE & DIAGNOST CADAVERICA,I-06100 PERUGIA,ITALY