The Cloud and the Cat — P.J. Thomas

When Snowball wonders outside of the house she soon finds herself lost and frightened with her new surroundings. She meets up with a bunch of alley cats that chase her, but she escapes with the help of a large dog, Duke. Later she is chased by the animal catcher and gets away by running into a park where she meets a dark cloud, Midnight that has run away from home. They become friends and in their effort to help each other set out on an adventurous journey that ends with Snowball finding her way back home, and Midnight being reunited with his family.