I have a theory about why dogs eat socks, chew on shoes, pee on beds etc.... What smells more like us than our socks or shoes? Really they have quite a bit of our scent on them. So for a dog that is really needing and missing companionship, it could be very comforting to chew on something that smells like us (kind of like sucking on a blanky). I am also concerned that there seems to be no awareness of the basic needs for companionship, shelter and exercise for this poor dog. I hope you can find a way to re-integrate the dog back into the household where it belongs.