I'd appreciate any advice we could get.

My neighbor just adopted a dog from a rescue.
The dog is a beautiful and friendly mutt. He appears to be a good
husky-shep-something else mix. He looks to be about a year old, most of it
in the pound.
The dog is emaciated. They have tried both leaving food all day and leaving
food only during feeding time. The dog doesn't want to eat.

Today I brought the dog cooked chicken, and while the dog agreed to eat it,
it was only reluctantly, and the dog still left little bits in the bowl that
I later had to hand feed him. When my dog gets a little bit of chicken in
the bowl, she finishes it immediately, and then turns over all of the dog
food to get the small bits. This dog was doing me a favor by eating at all.

What should we do?
Thanks