Greenhood exists in an area where there is a small racetrack or stable, a barn and a "lookout"(with people). The racetrack was designed for a dog race as we expected. It is funny that Vinci´s Mansion was not completed when Mafia 2 was released but a week later it was completely included for a hairless guy as a final mission so his story could have an epic final. You can find the game texts about betting on hound here .
Vinci´s Mansion was originally designed for Vito´s story. However according to 2k developers they were not able to finish it. A week later they released it in Jimmy´s Vendetta. It would be impossible to make so many textures and codes within a week.