Canine caliciviruses of four serotypes from military and research dogs recovered in 1963-1978 belong to two phylogenetic clades in the Vesivirus genus.

These CaCV isolates have restricted cell tropism, antigenic diversity and genetic variation. Further investigation will shed light on antigenic relation to other vesiviruses, and its pathogenicity for dogs and potential infectivity to other animals. Together with the previously reported CaCV strains provides significant evidence to support the formation of a new CaCV species in the Vesivirus genus.