Short term dog foster organization?

My elderly neighbor has a dog and he (the neighbor, not the dog) is heading in to the hospital for surgery. He doesn’t have anyone to look after the dog nor the resources to board him. I live next door and walk the dog on occasion but I’m going to be out of town for most of his hospital stay.

I’d hate for my neighbor to have to give up the dog AND I feel sorry for the dog.

Any ideas of organizations that offer short term foster or something like that?