I have a 13 year old mutt puppy (best dog EVER!) who started digging about 2 years ago. The vet told me that when dogs get old, they often do not want to die around their owners and that her time was probably short. Well, she is still here, a little sleepier, but still a joy. She STILL digs, but I think it is because the ground is so much cooler under there! Also, she is blind, and goes by scent, so maybe she is looking for something she cant see! Good luck on your problem. So far, nothing has worked on my baby. Unfortunately for her, I have choosen to tether her so she can not run when she is outside. I do this not only for my peace of mind, but also for her safety. One thing to try is placing your doggies droppings where it is digging. They say that helps....Good luck!