you know, this really might sound terrible but... that dog doesn't deserve that kind of treatment I believe we all agree on that, so my opinion is the next time you see him just take him and claim him as your own. Its perfectly understandable that you cant take the dog into an office with you so kinda get your car ready I dunno what the weathers like in your area but whatever you gotta do just don't let him suffer like that anymore. He'd be so much better off with someone who cares about him I seriously doubt theyd even miss him.