Little Rio broke my heart too.
I don't believe you can adopt a dog from rescue once you've given it up. If that were the case, can you imagine how many people would be dropping of dogs with expensive medical needs with plans to get them back after the rescue spent the money?
It seems unfair, in a way, but the goal of the rescue is to find a new forever home, not to reunite furbabies with the families who gave them up.
Anyway, TG that there are so many good rescues!