Before you check out dog parvo symptoms, you must first know what it is, what it does and how it is spread. This virus was initially found in’78 and within a two year time span it spread worldwide. Over the years the parvovirus has mutated into two different strains and a third may be evident in Vietnam, Italy and Spain. Each case of canine parvovirus Or CPV comes from the first two strains. At first it was felt that this virus would develop into feline panleukopenia, a feline parvovirus, but there is no evidence of this. All species have their own unique parvovirus that cannot be spread outside of the species.