Update on Canine Parvovirus: Molecular and Genomic Aspects, with Emphasis on Genetic Variants Affecting the Canine Host

Canine parvovirus (CPV), the etiology of hemorrhagic enteritis in dogs, was first isolated as CPV type 2 (CPV-2) almost 40 years ago, and was soon replaced by the emergence of new variant types. The major viral capsid proteins encoded by the VP2 gene are the sites where amino acids are often substituted, accounting for the unusual nature of this type of DNA virus. The alteration of specific residues has contributed to different antigenic variants which have affected the evolution of virus binding and host immunity to this virus. Sequence analysis of the VP2 gene and subsequent characterization have revealed three circulating CPV-2 strains, CPV-2a, CPV-2b, and CPV-2c, identified by mutations at amino acid residue 426. The latter strain displays increased pathogenicity in dogs and an extended host range. The present review article aimed at updating contemporary information on epidemiological studies and surveys from CPV field work. Moreover, we pointed out some sensitive and rapid diagnostic tools for detecting CPV in clinical samples, techniques which will be useful for health monitoring and management of CPV with currently available vaccines.