Had a similar problem with Molly (Australian Shepherd). She is my son's dog, but she is with my wife and I most of the time. When I put out my strawberry plants in our new strawberry bed she dug up two of them. No damage because now they are really spreading and doing well.
Dogs don't sweat to keep cool, that is why they pant. But cool damp earth is something they really like. Hence her attraction to my strawberry bed.
HA...dogs and digging....we have learned with our Abby (rescue dog - part lab, part aussie? or border collie?) to always have a spot JUST for her to dig in the garden. She LOVES to lay in her dark, damp hole!