This story is very poignant for me as my bayley was kept isolated in a garage and physically punished.
When he came to me Via Jane S he had the mental scars to prove it.
With love, understanding and a lot of hard work he has been transformed.
It can be done but it has to be done sooner rather than later.
Can you not persuade your relatives that what they are doing is wrong!
I'll give you my number if you think they would listen to behavioural advice and if they are not too stubborn to know what's good for their dog.
They do however need to understand what they are doing is making the dog worse for anybody to help them and this poor little doggie.
Best of luck in your efforts and If i can help with any advice please PM me.
Mark