Chance is a young, immature American bulldog owned by a young boy named Jamie who cares for him very deeply. Given his early life, he was abandoned as a puppy and sent to the pound. Fortunately, he was adopted by Jamie and given a home. His pet comrades are Shadow, a wise, old golden retriever and Sassy, a Himalayan cat who is constantly annoyed by Chance's antics and is usually tortured by him. Due to his immaturity, Chance has a tendency to get himself (as well as his pet comrades) in trouble. He considers Shadow an old fusspot and calls him "old timer," but still has respect for him. His fear of going to the bad place seen in the 2nd film leads him and the other to be left behind.
Chance with Shadow and Sassy in Homeward Bound: The Incredible Journey
Chance in Homeward Bound II: Lost in San Francisco