Hello,
When I was grooming I told everyone whom dropped off a dog three hours. Some would not like the time however It took me that long to do everything for one dog. Some would be done before and I would call the owners to pick them up. Most of the time they would come in as I was still working on them. That is working straight through and I took my time so the dog was as comfortable as possible. I did not want the dog nor the owner to leave not happy. All of my clients were happy with the results however if it has been over three hours and you still have not heard nothing I would call or even go and check on the dog. In this day and age you cant trust too many people. It may just be a case of too many dogs and not enough hands to clean them. Im sure your puppy is fine.
Tracy