The answer to the question: What are the names of the animals that fear they have been abandoned? is inside the article: Chance (voiced by Michael J. Fox), an immature and disobedient American Bulldog and the narrator of the film, explains that he is the pet of Jamie Burnford, but expresses no interest in his owner or being part of a family. He shares his home with Shadow (voiced by Don Ameche), a wise old Golden Retriever owned by Jamie's brother Peter, and Sassy (voiced by Sally Field), a smart-mouthed Himalayan cat owned by Jamie and Peter's sister Hope. That morning, the children's mother, Laura Burnford, marries Bob Seaver, and Chance manages to cause chaos by digging into the wedding cake in front of all the guests. Shortly after the wedding, the family has to move to San Francisco because Bob must temporarily relocate there for his job. They leave the pets at a ranch belonging to Kate, Laura's college friend. Shadow and Sassy start missing their owners immediately, but Chance sees it as an opportunity to explore and have fun. Later in the week, Kate goes on a cattle drive, leaving the animals to be looked after by her neighbor Frank. However, Frank does not see her message and thinks that she has taken them along, leaving the animals alone.  Worried by the disappearance of their host, the animals fear they have been abandoned. Shadow, refusing to believe that his boy would abandon him, resolves to make his way home.  Not wanting to be left alone on the ranch, Chance and Sassy decide to accompany Shadow on his journey., can you guess it ?
Shadow