I already posted once, but wanted to add something.
About 7 yrs ago I did this EXACT same thing!
The "owners" of a dog left him tied up, outside(with a fenced yard
) and every day I would drive by there, he was literally skin and bones!! I always took him food...well one day he was tangled up in the fence, and thought to heck with it, hes comeing with me!! And indeed, thats just what he did! And needless to say he (Peanut) lived with me about 2 yrs.
Until he was viciously attacked and killed by our neighbors dog.
The sad thing, the other "owners" never once put up lost ad's or anything, so you know they didnt give a rats behind that he was gone!!!