Wow. That's amazing. It totally reminds me of how my neighbors dogs were towards each other.
Their owners were seriously neglecting them and animal control could/wouldn't do anything about it so the older of the two dogs started trying to walk to the busy roads nearby as kinda a suicide mission or atleast that's what it looked like, but the other dog would take off as soon as she noticed that the older dog was gone and bring her back home. It was amazing to watch her realize what was happening and shoot off to go get her friend.