good for you!! and lucky for the dog you happend by.
I don't believe animals should be chained, they should be in a fenced yard, with enough room, but not chained. and should be able to reach the shelter!! as for the no food or water, I don't know if the dishes were just empty or not there at all? sometimes my cats dishes are empty or spilled and I don't notice, then wonder how long they were like that. but they have more than one food and water dish, so they are not without. especially water, that's important to them to have access to 24 hours a day!

so, I wonder what will happen to the dog now, if the owner got a warning, will they check back on the dog?