MacKenzie, a seven-year-old Chihuahua ,was named "America's Hero Dog" on October 19, 2020 (Credit: American Humane)

Dogs are often referred to as "man’s best friend." But MacKenzie, a four-pound Chihuahua, who was named winner of the 2020 American Hero Dog competition on October 19, 2020, is making the world a better place for humans and animals alike.