Kelly Booker, left, shows his son, Azzah, right, their long lost dog, Lilly the Shih Tzu, at the United Airlines cargo terminal Thursday, May 7, 2015, in Denver. Lilly, who disappeared nearly four years ago from her owner's home in west Denver on July 4, 2011, was found wandering the streets of the Chicago suburb of Elgin, Ill., and nursed back to health. She was identified by a microchip with her owner's contact information. (AP Photo/David Zalubowski)