One of my first rescue dogs was a Mastiff/Lab mix named Charmer.
Charmer grew to about 140 pounds, which is small for a mastiff. He was the gentlest dog I'd ever seen. He was also addicted to Frisbees.
So he chewed a hole in the stairwell's drywall to get onto the second floor. The hole was large enough for a full-grown man to climb through.
He went through obedience school twice because the first time, he didn't get it. When it was obvious he had separation anxiety, I rescued another dog, a blue merle Australian Shepherd I named Buddy. Buddy and Charmer were constant companions. And Charmer never did try to chew his way through the house again.
Charmer passed away from old age. On a Tuesday, he was running around the yard catching the Frisbee and having the time of his life. On Thursday, his heart began to fail and the next day, he was gone.
He lived a great life. And I was very lucky to be part of it.