Parvovirus CPV2 is a relatively new disease that appeared in the late 1970s. It was first recognized in 1978 and spread worldwide in one to two years.[SUP]
[2][/SUP] The virus is very similar to
feline panleukopenia (also a
parvovirus); they are 98% identical, differing only in two amino acids in the viral
capsid protein VP2.[SUP]
[3][/SUP] It is also highly similar to
minkenteritis, and the parvoviruses of
raccoons and
foxes.[SUP]
[4][/SUP] The early belief was that the feline panleukopenia mutated into CPV2. It is possible that CPV2 is a mutant of an unidentified parvovirus (similar to feline parvovirus (FPV)) of some wild carnivore.[SUP]
[5][/SUP] A
strain of CPV2b (strain FP84) has been shown to cause disease in a small percentage of domestic
cats, although vaccination for FPV seems to be protective.[SUP]
[6][/SUP] CPV2, however, does not cause disease in cats and does so only mildly in mink and raccoons, and is a virus almost exclusively affecting canines.[SUP]
[4]
[/SUP]Two more strains of canine parvovirus CPV2a and CPV2b were identified in 1979 and 1984 respectively.[SUP]
[5][/SUP] Most cases of canine parvovirus infection are believed to be caused by these two strains, which have replaced the original strain, and the present day virus is different from the one originally discovered[SUP]
[4][/SUP][SUP]
[7][/SUP] although they are indistinguishable by most routine tests. A third type, CPV2c (a Glu-426
mutant), has been discovered in
Italy,
Vietnam, and
Spain.[SUP]
[8][/SUP]