Significance of Gertrude's Pets

Gertrude's is a pet shop in the town of Naomi where Opal secures a red leather collar and leash for Winn-Dixie in exchange for sweeping the floors and straightening up every morning. Gertrude's is also where Opal and Winn-Dixie meet a new friend named Otis. He's in charge of the pet shop.