We took them home and everything seemed fine but for the first four days the puppy lost weight. She was born weighing 11.9 oz and by the Wednesday following her birth was down to 8.8 oz. While it is not unusual for a newborn puppy to lose up to 10% of their birth weight in the first day or so, the puppy's loss was at least 25%, so 1-2 days in I starting supplementing with formula. On Wednesday she leveled out and began to gain weight again. At just over five weeks, she is now above 4lbs and continues to thrive.
The pup currently resembles a pot bellied pig as we are feeding her 2-3 times a day as we accelerate the weaning process and she still has quite a bit of access to her mother so she can continue to have company and learn from her.