
Hi Mel,
It's very likely that these are scratches from the puppies' nails. They become quite fearsome weapons in a very short time! I suggest you get a pair of nail clippers and clip off the curved tip of each nail and see if the scabs stop appearing! Mum will also thank you, because the wounds the nails inflict on her undercarriage when they feed can be very painful.
Hope this helps.
:)