It was impressive when we recently learned that dogs could be trained to sniff out cancer and on-coming seizures. But did you know that dogs can also smell fluctuations in your blood sugar? This would be a cool party trick for a healthy dog owner, but for a diabetic, it could be the difference between life and death. In a just-published report on the burgeoning field of service dogs trained to assist diabetics, The Wall Street Journal's Kate Linebaugh gives the example of an eight-year-old girl named Abbie who was diagnosed with Type I diabetes at age four and could slip into a coma at night if her blood sugar dips suddenly. That's why Abbie's family keeps Gracie, a 70-pound Labrador, around. "The scenting part comes naturally," Abbie's mom told the paper. "They are hunting blood sugars instead of ducks."

Service dogs for diabetics isn't an entirely new concept. It's been around for a few years, though the number of service dogs in the field has been on the rise recently with as many as 30,000 in the United States today. Like with the cancer- and seizure-smelling dogs, though, researchers have taken an urgent interest in finding exactly now dogs' noses can detect low blood sugar and possibly invent a device that does the same thing. They use the scent of human sweat with different blood sugar levels to train the dogs but aren't sure exactly what it is the dogs are smelling that tips them off.

They're so far stumped. "Whatever is being secreted in that drop in blood sugar … we just don't know what it is," Dana Hardin, an endocrinologist who's working on figuring out how these dogs' noses work at pharmaceutical giant Eli Lilly, told The Journal. Such a device would potentially save the lives of diabetics with a condition called hypoglycemia unawareness who don't even realize when their blood sugar dips. "They don't get the signs" Hardin explained. "They just can be having a normal conversation, go from feeling fine to passing out."

Who knows what other breakthroughs might come from studying these diabetes-sniffing dogs. They could provide some insight into the seemingly impossible search for a cure or make the lives of those living with diabetes easier. Inevitably, providing the benefits of the service dogs to more people is a big goal. Since these canines cost around $20,000 a piece and trainers keep waiting lists that are dozens of diabetics long, the amazing animals are hardly an option for everyone.