Take a 140+ m rope, fold in half such that there's a loop. Affix a sizeable weight near the loop such that it is stationary on one side of the rope and the other side moves freely through the weight. Lower the loop down such that it is positioned, open, at the dog's level (like a snare). Wait for the dog to walk through the loop such that front paws are on one side and back paws on the other (obviously need a camera…
Lower a baby down to it on a rope. The baby can grab the dog.
Backup plan:
Fill the hole with water. Puppy will float.