my bitch had her puppy 3 days  ago, last night we were up all night with excessive panting, she would jst start to drift of to sleep then get up an move again trying to dig, wake up the puppy so it would feed, i think i remember my other bitch doing this but it was a couple of years ago! memorys not wat it was lol, shes quite happy now lyin cuddled up to her baby  who is the only one so is getting fatter by the hour, i did give her some rescue remdey which calmed her down, she was fully checked over by the vet the day after whelping and was fine.

Hi Sammye,
The panting is usally pain. If she is fine in every other way with no adnormal discharge. I think you will find it is her womb contracting back. It can happen a little worse when she is feeding.
I remember breast feeding my babies and it was sometimes as painful as the labour.
Congratulations on your little ones.

Agree with denese.  This is perfectly normal, and some bitches go on panting far longer than others.

If your vet has checked her out, I'm sure that she is just experiencing pain.  And remember just how hard her body is working now.