Four shelter dogs rescued from slums and abandoned lots around Sao Paulo were trained as "ball dogs" for an exhibition tennis match this week at the Brazil Open.
The dogs playfully ran after the balls that went out of play and reluctantly returned them to the players and dog trainers during the match this week.
"We want to show that abandoned dogs can be adopted and trained," said Andrea Beckert, a trainer from the Association of Animal Wellbeing.
"After all, it's not easy to get a dog to only pick up the lost balls, and then to give them up!"
The four dogs were Frida, Mel, Isabelle and Costela.
"Costela" is the Portuguese word for "rib."
"When we found him abandoned in an empty lot he was so skinny and ravaged by ticks that we called him Costela," Beckert said.
She said the association is currently sheltering about 1,200 dogs and hopes to raise awareness with the "ball dog" initiative.
On Thursday the dogs donned orange bandanas and were cheered on for about a half-hour as they dashed after the lost balls. The competitors, Spain's Roberto Carballes Baena and Portugal's Gastao Elias, played along.
On Sunday the dogs also participated in the awards ceremony.