Dilema

[Raiye]

What would you do?

You take your kid to the park and tied to the swings with blue string is a dog. He's covered in open sores and obvious mange, as you say hello, the fleas tango over your hands. His eyes are all crusty and his ears are full of mites. He is soo skinny you can count every single rib and he has pressure sores on his elbows and behind.
No one is around, the dog is alone.
You take him home. Call the dog warden as you should and sign the papers to keep for he required 28 days as the local pound has a terrible rep and you know they wouldn't treat him very well.
The following day you are at the vets, you get him deflead, de wormed, and start his treatment to clear his mange. You give him a bath, a good meal and a comfy bed.He is only a baby, about 8 months guesstimate with a really lovely nature. A darling of a dog.
You are at work a few days later when a neighbour that you know by face happens by with a dog the spitting image of the one you have found. This dog is in the same state as the other, half bald and half starved. You strike up a non committal convo and discover the dog you found was the brother to this dog (its obvious just from looking) and that your dog has been dumped by her brother. They are even walking this dog on the same blue string your boy was left tied with. Basically you have found the owner of your dog. The owner lives on the same estate as you and there is every chance you could bump into them while walking your recovering itchy skeleton.
What would be your next action? What would you do?