Cinderella, a 6-year-old brown-and-white female mixed pit bull, spent more time than any of the dogs at the Society for the Prevention of Cruelty to Animals’ facility in Long Beach.

For months, video clips that circulated on social media and local newscasts told the tale of 6-year-old Cinderella, a brown-and-white female pit bull mix living at a Long Beach shelter but looking ...