To make sure both dogs got on well with AnnaSophia Robb, she was brought in early to get acquainted with them and give treats. By the time shooting started, they considered her safe.
Director Wayne Wang wanted to use Picardy Shepherds because he thought they looked similar to the depiction of Winn-Dixie on the book cover and would appear familiar to its readers. Dogs were brought from France when none were available in the U.S. (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.
Winn-Dixie was played by multiple Picardy Shepherds, a rare breed from France. The DVD extra "Diamond in the Ruff" shows the two principal dogs, Scott and Lyco, but producer Trevor Albert mentions at 18:00 and 40:26 in the DVD feature commentary that, in all, four dogs were used. At 00:36 in AnnaSophia Robb's commentary "Meet Winn-Dixie" she mentions that the stunt dog Tasha jumped over the flour.
Jennette McCurdy revealed in an interview with The Financial Diet that her mother wanted her to audition for the part of Opal. But Jennette overheard her agent telling her mother that producers wanted an "ethereal beauty" for the part and considered Jennette to be more "homely"