Rotavirus in diarrheic rabbit : prevalence and characterization of strains in Italian farms.

The multifactorial rabbit enteropathy has a great importance in rabbit meat production for its economical impact. Stating the pathogenic role and importance as primary agent of rotavirus, the purposes was to estimate the prevalence of lapine rotavirus (LRV), identified by negative staining electron microscopy (nsEM), on samples from rabbits showing either a “generic” enteropathy or lesions referable to mucoid enteropathy-caecal impaction and then to relate their presence with the symptoms and lesions observed. During the 2002-2007, 243 samples taken mainly from rabbits showing catarrhal, haemorrhagic or necrotic entero-tiflitis, mucoid enteropathy and caecal impaction were examined. By nsEM, the presence of viral particles was observed in 45.3% of them; rotavirus was identified in 16.0%, coronavirus-like virus in 24.7%, parvovirus in 9.0% and enterovirus-like virus in 5.8% of the positive samples. In addition, adenovirus, calicivirus and reovirus were sporadically found and, in 29 cases, 2 or 3 different viruses were contemporarily observed in association in the same sample. Using the criteria for the classification of rotavirus strains based on the VP4 (P type) and VP7 (G type) genotyping, almost all the strains were characterized as P[22] G3 confirming the presence of the newly-recognized rotavirus P[22] VP4 allele in Italian rabbits. The availability of the results of microbiological and parasitological analysis allowed to correlate nsEM observations with the contemporary presence of others pathogenic agents such as rotavirus, enteropathogenic Escherichia coli (EPEC) and Staphyloccoccus aureus in suckling rabbits; EPEC, Cl. spiroforme and flagellate protozoa in the others. The pathogenic role and importance of rotavirus as primary aetiological agent rabbit enteritis are discussed.