Chance is an American bulldog breed. The role of Chance was portrayed by an American bulldog named Sure Grip Rattler. The production company did have multiple American bulldogs on set to film different scenes, but Sure Grip Rattler was the star all of the main scenes as Chance.
To prep for the movie, the animals underwent 7 months of training. Following "Homeward Bound," Chance went on to work for the fire department helping to sniff out flammable liquids.
The roles of the other two animals, Sassy and Shadow, were also played by multiple dogs and cats. There were eight cats used to portray Sassy, and trainers from Jungle Exotics taught them to respond to a buzzer for food, which was taped to one of the dog's collars, which is how the directors persuaded the cat to run towards the dogs in some scenes.