MacKenzie, a 4-pound Chihuahua from New York, has been named America's most heroic dog at the American Humane Hero Dog Awards. The winner was chosen by public votes and a panel of celebrity animal lovers. MacKenzie works for The Mia Foundation, which rescues animals born with birth defects who cannot be with their mothers. She cares for baby rescue animals of all species and sizes, and teaches them how to socialize, play and have good manners. She also interacts with children at schools, teaching them kindness, patience, and acceptance of physical differences.