You were obviously concerned about the health of this baby, otherwise you wouldn't have posted.
You have already said he is very runty, the running in circles indicates 'wheeling' which is a big sign of ill health, the most severe being brain tumour/damage and the least being inner ear problems.
It is of course possible that this baby is some sort of hairless... but personally with all the other indicators you have said *yourself*, it doesn't really matter does it?
I know that euthanasia is not a nice thing to have to do, but honestly, and i'm going to sound a cow saying this... if you can't bring yourself to do it, even in the most extreme of cases, you should not be breeding.