
Yes a heat pad is needed, provided there is room for the pups and Mum to move to a cooler area if they want there is no problem, you will see them migrate around the whelping box, sometimes in puppy piles other times spread out on their own
Pups have to be kept extra warm over the first couple of weeks to prevent the canine herpes virus[can be present and you don't know] taking over and killing them.
Good Luck with your litter.