These 12 breeds—and one mutt—represent the most popular dogs in the U.S. But popularity has its down side. Too often, these breeds are victims of puppy mills--mass breeding facilities that churn out puppies to meet the demand. Cheeky Monkey Jewelry supports the Puppy Mills campaign of The Humane Society of the United States.

Animal shelters and rescue groups have lots of great dogs—mixed breeds and purebreds—so make adoption your first option. Or go to a purebred rescue group, or a responsible breeder. Avoid pet stores or pets sold on the Internet! Find out more at humanesociety.org/puppy.