To ensure that both dogs got along well with AnnaSophia Robb, she was brought in early to get acquainted with them and to give them treats. By the time the shooting started, they considered her safe.
The director Wayne Wang wanted to use Picardy Shepherds because he believed they resembled the illustration of Winn-Dixie on the book cover, ensuring they would look familiar to readers. Since no Picardy Shepherds were available in the U.S., dogs were brought in from France (08:55 in the DVD commentary).
The film's mouse was played by a rat. The choice was made carefully because while a mouse would have been preferable, rats are much easier to train.
Multiple Picardy Shepherds, a rare breed from France, played the role of Winn-Dixie. In the DVD extra "Diamond in the Ruff," the two principal dogs, Scott and Lyco, are featured. The producer (see Trevor Albert) mentions in the DVD feature commentary at 18:00 and 40:26 that four dogs were used in the film. Additionally, at 00:36 in AnnaSophia Robb's commentary titled "Meet Winn-Dixie," she notes that the stunt dog Tasha jumped over the flour.
In an interview with The Financial Diet, Jennette McCurdy revealed that her mother encouraged her to audition for the role of Opal. However, Jennette overheard her agent telling her mother that the producers were looking for an "ethereal beauty" for the part and thought of Jennette as more "homely."