Oh Judith, I'm sorry you are having trouble with your son's dog. I'm in the same boat with my daughter's dog. She travels and I dog-sit. Her dog is so bad that we named her "Trouble" when she was a tiny puppy! She is a total mutt that was supposed to be a German Shepherd. Her mother wasn't in the same county with a German Shepherd ... ever!
She is about 2 years old now and still eats anything made of fabric (her favorites are rugs, clothing, and socks), and anything made of wood! She pretty much stays crated at my house. Yikes!! And, yes, we've had all kinds of dogs in the past, but this one is something different. ...