We have had our 6 year old lhasa apso for 4 years. We got him from pets4homes (I know how bad that is now but didn't at the time and desperately wanted a lhasa but not a puppy). He is a gorgeous dog. So loving and calm and brilliant with the dds (13 and 10). He was fine for the first couple of years when we used to leave him to go out and would happily stay a good 4 hours on his own. Suddenly one day a couple of years ago we came home and everything had been knocked off the window sills. It was really odd but we thought something may have just spooked him. After that it got gradually worse. Even if we left him for an hour he would chew through wires, scratch at doors and break stuff. He used to scratch so hard his paws would bleed. We had to introduce a crate. We did this gradually and he loved being in it when we were home but when we ever went out he would try to escape the crate to such an extent we would come home and he would be dripping with saliva and blood. He has broken out of two crates now, damaged his teeth and paws and is trying to make his way through a third. Myself and dh have changed our work patterns so he is never left all day or for long periods. Only if we go out for a meal as a family or when my dh is working away and I need to go to the school. Every time we come back it is so distressing not to mention the absolute hell my poor dog is going through. He physically shakes when we get ready to leave home. I have read such a lot on this and I have tried all the training recommended (get ready to leave but don't, etc). We always leave a radio/tv on but it doesn't help. He also barks the WHOLE time we are away so is annoying neighbours. He is fine in the car but obviously with the warm weather I can't keep leaving him the car. We really are at our wits end. I have spent another weekend unable to take the dds to see a film they wanted or to do anything as I can't leave him on his own so it is really affecting their lives too.
I strongly feel he needs to be with someone who never goes out and would make an excellent companion for an older person. I called a dog rescue up who have put us in touch with a foster carer. She has spoken to me and said she has a place for him at her house where he will go until they find him a permanent home (which she is confident she can even after I told her everything). She told me that we need to be sure because once signed over we can never get him back. I spent most of yesterday in tears. The thought of dropping him off with a stranger miles away and never seeing him again makes me and the rest of the family distraught. Likewise the thought of seeing him in such major distress every time we go out is also awful. We all love him so much and want to do the right thing. We don't have anyone that could sit with him every time we go out and being a young family he does need to be left some of the time.
What should I do 
. They are holding his place for a week so I need to decide.