You've probably seen ball boys and girls at tennis matches, those young folks who dart onto the court super-quick to snatch up balls that have faulted or to give fresh balls or towels to the players. And you're probably familiar with dogs fetching tennis balls in the park. It's likely, however, that you've never seen a dog work as a ball boy at a tennis match. Until now.

Four dogs from a shelter in Sao Paulo, Brazil retrieved tennis balls and returned them to players and other linesmen during the Brazil Open tennis tournament as part of an initiative to dispel concerns about shelter dogs and raise awareness about adopting them. "The idea is to show people that a well-fed and well-treated animal can be very happy," event organizer Marli Scaramella told Fox News Latino.