
At 6 weeks in whelp the pups would be absorbed or aborted, to early to survive.
Be very careful in case it is a lack of calcium, I have know two people loose their bitches to this as pre-eclampsia is nto that common.
Is there any swelling in the legs or signs of water retention, as these can be signs. Both the cases I knew of the bitches just dropped down dead while heavily pregnant, but not this early in pregnancy, nearer the due dates.
In one case the daughter of one of the bitches was showing similar signs in her pregnancy and was saved by quick intervention.