Stealing Dog?

Tr

So my friend has a co-worker and her family staying with them for a couple weeks because their house was flooded. With them, came their pup.

She's so underweight you can count her bones. She has bedsores from being in her crate literally all the time. She's so beautiful. My friend says since the pup has been with them he's been sneaking food to the dog and letting it out as much as possible. It's a really good dog; she listens really well, she's not aggressive towards their dog, kitten, or kids. He's tried to convince the owner to give the dog to someone who will love and care for her, but the owner refuses because she "loves"her, even though she's suffering and not being cared for.

My question is....my friend has asked if I'd take the dog, because he knows I've nursed animals back to health before and I know how to care for a malnourished dog.

Would it be wrong for us to steal this dog? I know she's not ours and the owner refuses to give her away, so we'd have to go get her while the owner was at work. I'm so torn. I can't leave an animal in that situation, but I also don't know if that is a reason to just take someone else's dog....