According to the Wall Street Journal, Service dogs can even pick up signs of dangers of diabetes in people:
"The dog's accuracy and speed can beat medical devices, such as glucose meters and continuous glucose monitors, according to doctors, owners and trainers. With their acute sense of smell, the dogs—mostly retrievers—are able to react to a scent that researchers haven't yet identified.
For centuries, doctors diagnosed diabetes by identifying sweetness in the urine of a patient. That scent comes from glucose that isn't absorbed when a person lacks insulin, but the chemicals produced during low-blood-sugar incidents have yet to be identified.
"Whatever is being secreted in that drop in blood sugar…we just don't know what it is," says Dana Hardin, a pediatric endocrinologist who works for Eli Lilly & Co. in Indianapolis. Her goal is to identify what chemical compound the dogs smell, "not only to train dogs but to possibly make a device," she says.
Most of the interest in diabetic-alert dogs comes from people with Type 1 diabetes—and parents of children with Type 1—because they are more susceptible than people with Type 2 diabetes to serious problems of low blood sugar. Type 1 diabetes is an autoimmune disease characterized by the absence of insulin production, and requires daily insulin injections. People with Type 2, which is brought on by a combination of genetics, inactivity and obesity, have trouble processing insulin but don't necessarily require external insulin.
Incidence of Type 1 has been rising in the U.S. by about 2.5% to 4% a year for reasons scientists can't explain, according to several large-scale studies published in peer-reviewed medical journals. The number of people with Type 1 diabetes in the U.S. is between 1.3 million and 2.6 million, accounting for 5% to 10% of the total diabetics.
Type 1 diabetics work to balance their daily intake of carbohydrates with external insulin. Prolonged high sugar levels can lead to complications such as heart disease, kidney failure and neuropathy. But trying to keep sugars at a low level raises the risk of hypoglycemia, which can be lethal, particularly if a patient loses consciousness while driving or alone."
Perhaps it should not be surprising to learn that some dogs share their gift of sight with other dogs as well: