Can Dogs Detect Low Blood Sugar?

It’s no secret that our canine companions possess a remarkable sense of smell, but did you know they’ve used it to save lives by alerting patients to health problems before they even occur?

Dogs are trained to recognize behavioral changes in their owners that signal the onset of health problems like epileptic seizures and heart attacks. Trained dogs have also sniffed out various tumors like lung cancer, colorectal cancer, breast cancer, melanomas, and bladder cancer.

Patients with type 1 diabetes are required to test their blood glucose several times a day to make sure their sugar levels aren’t too high or too low. Dangerously low blood sugar events can occur suddenly without warning and be serious and sometimes fatal.

Medical detection dogs work by alerting or waking up their owners whenever their blood sugar drops to the level of hypoglycemia, but scientists have never understood why some dogs can be trained to spot the warning signs and exactly how they pick up blood glucose changes. Now, new research suggests they’re smelling a common chemical called isoprene, which is found in human breath.

In the study, blood sugar levels were gradually lowered under controlled conditions in 8 women with type 1 diabetes. The researchers then looked for chemical signatures using mass spectrometry to detect the presence of isoprene. They found that isoprene levels rose significantly, and in some cases almost doubled, at the onset of hypoglycemia.

Although the researchers suspect the elevated isoprene is a byproduct of cholesterol production, they have yet to determine why levels of the chemical rise when patients have very low blood sugar.

Still, dogs may be sensitive to the presence of isoprene and can be easily trained to alert their owners when hypoglycemic events occur. Further studies are needed, but with these new findings, scientists may be able to develop new tests for detecting hypoglycemia and reduce the risk of potentially life-threatening complications for patients with diabetes.