That is why it usually replicates in actively growing cells such as the epithelial cells lining the gastrointestinal tract. There are two forms of canine parvovirus. Canine parvovirus 1 is a minute virus of canines only which is taxonomically distinct and usually causes a mild diarrhea. Canine parvovirus 2 is the classic form of the virus which is normally associated to a parvovirus infection and disease. It has also been known to infect cats and is closely related to raccoon parvovirus, fox parvovirus, feline parvovirus and mink parvovirus.
Parvovirus has a remarkable host-range mutation, which means is can jump species by mutating.
We now have a mix of the 2a and 2b forms. Antibodies against the original CPV-2 form do not work as well against the newer forms, which keeps the virus from being overcome by an immune response. Pathogenesis CPV spreads rapidly from dog to dog via oronasal exposure to contaminated feces. Virus replication begins in lymphoid tissue of the oropharynx, mesenteric lymph nodes and is disseminated to the crypts of the small intestine via viremia. Parvovirus causes destruction and collapse of the crypt epithelium in the GI tract.