[HarleyHOO]

6 weeks is very young so I hope you've read up on what needs to be done to care for such a small baby....

I have no clue what would cause this "hardness." However, given his/her age, I'd take him into the vet just to be on the safe side. Doesn't sound normal to me, but then again, I've never been with a pup that young. Maybe he's constipated? What are you feeding him? I know that when they're really young, they go to the bathroom (both pee & poop) ALOT due to their small bladder/stomach. However, if he's not going poop on a regular basis, this leads me to believe something's wrong, like some sort of blockage. Please get him checked out to be on the safe side.

Hope everything works out well. Keep us updated. God bless