Assistance with resolving separation anxiety issues

You already see they do the most destruction within the first 20min you are gone. You are going to have to retrain her to a crate to teach her that the crate is NOT a bad thing. First, for a crate, you you might want the one constructed of metal bars and a plastic insert bottom. If she is like my shepherd she will immediatly chew up the bottom. We replaced our bottom with a thick piece of wood so he couldn't slide it out or chew it up. This cage has 2 handles on the door to keep it closed. Does she go into her cage willingly or is it a fight? If she is fighting you, you have to make her want that bed. Give her the best treats in there. Feed her in there. Do all this while you are with her and the door is open. After a few days put her in, close the door then give her the best treats. Feed her in there with the door closed. As soon as the treat or food is gone, then let her out. This could take up to a month to get her comfortable being inside the crate again. Once she is ok going in then you move to the next step.(you can actually do some of this at the same time you are retraining to the crate.) She gets distressed when you leave. You now have to desensatize her from routine sounds that tell her you are leaving, like keys, doors, purses, etc. Walk around the house shaking your car keys for a few minutes several times everyday while she is in the crate. DO NOT LEAVE. Just get her used to the sound. Do this for about a week. Week 2, put her in the crate and with keys in hand so they make noise, open and close the door you usually leave from. Do it over and over and over again several times a day for the week. Do not go out the door. Again, just getting her used the noise. Week 3, now you get to go out the door. Again, have keys in hand. Go out for a minute or two. It works best if you can hear her getting upset. As soon as you hear her making noise come in. You probably already guessed it, but do this several times a day for a week or two. You want to work up to the point that you can stand outside for 20 min. with no noise from her inside. Once she figures out that the noise from keys, purses, doors, etc. means nothing she will be alot more calm when you leave. Which means ahe will be alot less destructive and happier when ahe is in her crate. My shepherd suffered severe seperation anxiety. The dog cost me $5000 in damage from his problems before we figured out what was going on. He too is a shelter dog with a bad past. Now we have had him 8yrs and he is one of the best dogs I have ever had. In fact, today we forgot to crate him when we left. We were gone almost 7hrs. He didn't touch a thing!! I hope this helps. If you run into issues with any of this drop me a line. I will help anyway I can. You did a great thing when you decided to foster this dog. Don't give up on her. It will eventually work out. I know it sounds like alot and it certainly will take time. But it is well worth it in the end. Good luck.