My ex adopted a fox hunting dog in a similar situation. Abandonded on a hunt, nearly starved to death, with a number literally spray painted on her side. Even tried to 'do the right thing' and reach out to the owner, but they told us to leave her in the woods.
Tossed their fancy tracking collar in the brush and took her home for her first warm bed and a steady diet. Those dogs aren't bred or raised to be house pets, but I don't regret having her one bit.
Dropout's viral marketing is crazy