It was a quiet night, and Dorrie Nuttall was fast asleep. Her seven-year-old son was sleeping next to her hooked up to a machine, which was supposed to alert her if his glucose levels were too low. The alert never came. Not from the machine, anyway. Jedi, Luke’s adorable diabetes-sniffing dog, started jumping on and off the bed. Nuttall didn’t wake up, so Jedi took it up a notch.