Hello Tina, I'm Dr. Deb and will do my best to help you today.
I'm sorry for this concern for Indy but there actually can be several different reasons why a bitch can pant post-whelping:
1. She could be running a low grade fever which is commonly seen after whelping for about 24-48 hours. If you have a rectal thermometer, you can take her temperature. Normal is between100 and 102.5. If this is the problem here, then I would expect her panting should subside within the next several hours (
2. She could be in the early stages of a uterine infection or metritis. The signs associated with this condition might include a foul-smelling brownish or reddish brown vaginal discharge, anorexia, lethargy, fever, decreased interest in the pups.
These dogs will need antibiotics for the problem to resolve.
3. Low calcium aka Eclampsia (LINK) especially if she's a small dog and has a large number of puppies to feed. Supplementation with Calcium Tablets (available at most pet or grain stores) may be something to consider if this problem is suspected. Tums can also be given if calcium tablets can't be purchased right away.
If this were my dog, I would take her temperature but wouldn't get too excited if it's high (>102.5).
I would monitor the color and smell of her discharge. If it smells, then a vet visit may be prudent.
But if she's otherwise eating and taking care of her babies, then I might give her another few hours since the panting may very well stop of it's own accord.
I hope this helps. Deb