The parvovirus family contains more than one virus.  I know nothing about
the dog version.  B19 infections in non-pregnant humans with intact immune
systems range from sub-clinical (most common) to mild rash/fever (most
kids) to a 6-8 week illness with prominent joint symptoms (many adults).
It should not be a major problem for most breastfeeding moms and healthy
babies.  Most adults are immune; there is about a 1% risk to the fetus if
mom is *exposed* to the illness in the first half of pregnancy (about a
50% chance mom is not immune, about a 10% chance she'll get sick, about a
10% chance if mom gets sick that baby will be affected=overall 1% risk).
In the first half of pregnancy, it's generally an "all-or-nothing" issue:
baby makes it and does ok or fetus dies.  It doesn't cause defects.  I
will check parvovirus b19 titers for pregnant women who have a high risk
of exposure (day care workers, etc)--most of the time they are immune and
can relax about it.

--
Anne Montgomery, M.D., I.B.C.L.C.
[log in to unmask]
St.Peter Hospital Family Practice Residency
Olympia, WA