Delivery of first puppy takes place during second stage of labor. Mother can go for rest after the first puppy is born that can be of 15 minutes to 2 hours. After this resting period, she will strain again for puppy and second puppy will be born. So, you should wait for maximum 2 hours for the second puppy to deliver. If mother is straining for 2 hours without any results then take her to vet immediately.
