In the middle of a raging thunderstorm, a traveling circus accidentally leaves behind some very precious cargo - a baby zebra (voiced by Frankie Muniz). The gangly little foal is rescued by horse farmer Nolan Walsh (Bruce Greenwood), who takes him home to his young daughter Channing (Hayden Panettiere). Once a champion thoroughbred trainer, Walsh has given up horse training for a quiet life with Channing on their modest Kentucky farm.
The little zebra, or "Stripes," as Channing calls him, is soon introduced to the farm's misfit troupe of barnyard residents, led by a cranky Shetland Pony named Tucker (voiced by Dustin Hoffman and Franny (voiced by Whoopi Goldberg), a wise old goat who keeps the family in line. The group is joined by Goose (voiced by Joe Pantoliano), a deranged big-city pelican who's hiding out in the sticks until the heat dies down in Jersey. The un-aptly named bloodhound Lightening (Snoop Dogg) keeps a lazy eye on goings-on at the farm - in between naps.
The Walsh farm borders the Turfway Racetrack, where highly skilled thoroughbreds compete for horse racing's top honor, the ultra-prestigious Kentucky Crown. From the first moment Stripes lays eyes on the track, he's hooked - he knows that if he could just get the chance, he could leave all those other horses in the dust. What he doesn't know is...he's not exactly a horse. But with characteristic zeal, he devotes himself to training for the big time, with a little help from Tucker, who has coached a host of champion racehorses in the past.
Channing has a similar ambition - she longs to train as a jockey, but her protective father refuses to let her compete in the potentially dangerous sport. But Walsh can't ignore her enthusiasm (or her stubbornness) for long, and she convinces him to come out of retirement to train her and Stripes for the Kentucky Crown.
The neighboring Estate is run by the ruthless queen of the Kentucky racing circuit, the incredibly wealthy and exceptionally coldhearted Clara Dalrymple (Wendie Malick). Stripes constantly battles the ridicule of the Estate’s thoroughbreds-in-training, led by spoiled bully Sir Trenton's Pride (voiced by Joshua Jackson), who taunts him relentlessly about his lack of breeding and…unusual appearance. But the Estate is home to some kinder residents, particularly Sandy (voiced by Mandy Moore), a beautiful mare whose admiration and affection for Stripes further enrages his rival.
Stripes makes some friends down at the track as well, most notably the manic horsefly duo Buzz (Steve Harvey) and Scuzz (David Spade), whose love of song and dance is eclipsed only by their love of hot dogs and horse poop.
As he thrusts himself into a world of elite athletes, intense competition and enormous stakes, Stripes must prove he's fast enough and tough enough to run with the big horses if he wants to land in the winner's circle at the legendary Kentucky Crown.
Some champions are born, not bred!