Old and Novel Enteric Parvoviruses of Dogs

Abstract

Parvovirus infections have been well known for around 100 years in domestic carnivores. However, the use of molecular assays and metagenomic approaches for virus discovery and characterization has led to the detection of novel parvovirus species and/or variants in dogs. Although some evidence suggests that these emerging canine parvoviruses may act as primary causative agents or as synergistic pathogens in the diseases of domestic carnivores, several aspects regarding epidemiology and virus-host interaction remain to be elucidated.

Keywords: bocaparvoviruses; chaphamaparvoviruses; dog; emerging parvoviruses; enteric viruses; protoparvoviruses.

Figure 1

Schematic representation of canine parvovirus prototype (CPV-2, genus Protoparvovirus) (A). ORFs organization of genome and its transcriptional strategy (B). The genome presents terminal palindromic sequences that form complex hairpin structures at the 5′ and 3′ ends. These structures serve as the origin of DNA replication and help encapsidation (packaging) of viral DNA. The 5′ ends of RNA transcripts are capped (black circles), and the 3′ ends are polyadenylated (An). VP1 and VP2 are encoded in the same mRNA.

Figure 2

Canine Bocaparvovirus: ORF genetic organization and replication strategy. The genome is depicted as a single line terminating in enclosed hairpin structures. Segments encoding the non-structural proteins (NS1, NS2) are shaded in red, the capsid protein (ORF2) is shaded in green, and the NP1 (ORF3) is in yellow. A solid arrow denotes the RNA polymerase-II promoter; polyadenylation sites are indicated by the letters AAAAA.