mom caring for runt

Question
We have been raising lab puppies for about 20 years.  With many successes and a few sad incidences.  This is a first for me and I want to find out more about a dogs instincts towards a runt in the litter.  Our 3 year old lab "M" had a litter of 8 puppies last year (2 heat cycles ago), 1 died on day 2(no apparent reason).  There was not a runt in the litter.  We bred M again this year and expected at least 8 pups.  M is in very good health and is an excellent mother - very attentive and caring.  Well she delivered 3 puppies five days ago - one chocolate, one yellow and one black - all females.  Well, Blackie is VERY tiny - unfortunately I never acquired scales, but I would guess about 1/2 pound.  Took her a while to nurse but with our assistance she got the hang of it.  Blackie seems to be doing what she needs to do - she nurses, snuggles with litter mates, etc.  M is taking very good care of all three of them.  But we have seen some bizarre behavior in M.  She is very nervous and restless when she hears Blackie cry.  She picked Blackie up in her mouth and I just about lunged into the box to grab it.  Then I stayed close and watched as M circled around the box, found a spot and laid down, placing Blackie near her tummy.   M is an awesome mommy in my book.  She obviously is giving Blackie the extra nursing time she needs.  This has continued for 5 days but I think M takes it a bit too far.  The poor pup is "man-handled".  Now M wants to take Blackie out of the box.  She has "escaped" from her whelping area and brought the pup up to the family room and circled around.  We brought them both back to box.  The past few times I have let M outside, she has gone to the barn and started digging.  A little while ago she tried to bring Blackie outside - I'm guessing she wants to bring her to the hole she dug.  As far as I can tell, M is taking very good care of Blackie.  Could there be more to it?  Could she be trying to abandon Blackie.  We believe in "survival of the fittest"  so we're trying not to interfere too much but I do try to stop M from carrying Blackie around the house and I won't let her take the pup outside.  This pup has made it 5 days so I tend to believe it is strong enough.  If M refused to care for this puppy I would understand better.  What is going on?

Answer
Hi Sheila. To me, it sounds like maybe mom is trying to find Blackie a new place to stay. Does this little puppy cry a lot? If so, that is probably frustrating mom because she's not sure what to do to help her puppy. Dogs seem to know when something's wrong with a puppy that we can't see. I have seen this in a Great Dane bitch once. She would take care of the smallest puppy, almost ignoring the rest. She then got to the point where she was trying to pack the puppy off. She did this once, and then returned to the rest of the litter. It's untelling why dogs do these things, I don't think anyone really knows for sure. The best advice that I can give you for now is to consider taking this puppy from her and raising it yourself. If mom keeps packing it around, it may accidentally get killed, even if that's not her intentions. I know this isn't very much help. I'll talk to that Dane breeder and see is she has any better insight to this problem than I do. I'll let you know what I find out.