To date, four viruses have been identified as the essential causes of severe enteritis in dogs: Canine Parvovirus, Canine Coronavirus, Canine Rotavirus and Canine Distemper Virus. Canine Parvovirus has been found to be responsible for approximately 27% of canine diarrhea. The family Parvoviridae comprises two subfamilies: Parvovirinae, which infects vertebrates and is classified into three genera, Parvovirus, Erythrovirus and Dependovirus; and Densovirinae, which infects insects and is further classified into three genera, Densovirus, Iteravirus and Contravirus. Parvovirus is among the smallest animal DNA viruses, with the virion exhibiting a diameter of between 18 and 26 nm. The genome is comprised of single-stranded DNA of approximately 5,000 bases encoding two structural (VP1 and VP2) and two non-structural (NS1 and NS2) proteins.