I don't ever leave dogs unattended outside for extended periods of time. My sister had hers stolen from her yard over the dinner hour. My neighbour had hers poisoned. Fortunately Andy was known by most of the neighbourhood and sister did recover him but the neighbour's dog died. Hard lessons learned. I would also worry that the digging could occur by a fence and the dog would then be "in the wind". If I am there watching, even from inside the house, then I can work on eliminating the behaviour. Like the idea of a digging box, don't like using something that could cause burning and inflammation.
