We present three cases of fatal dog maulings of infants placed in mobile infant swings, a phenomenon not previously described in the literature. In each case, the victim was left in a mobile swing, unsupervised by an adult, and the attacking dog was a family pet. Case 1 involved an 18-day-old male infant attacked by a pit bull; Case 2 involved a 3-month-old male infant attacked by a Chow Chow and/or a Dachshund, and Case 3 involved an 18-day-old female infant attacked by a Labrador-pit bull mix. These cases not only underscore the importance of not leaving young children unattended in the presence of pet dogs, but also raise the possibility that mobile swings may trigger a predatory response in dogs and thus may represent an additional risk factor for dog attack.