Dogs possess an amazing ability to sniff out changes in human physiology, even drawing attention to diseases such as cancer. Their ability to detect low blood sugar (hypoglycemia) and alert humans in well established. People with type I diabetes can experience abnormal drops in blood sugar – potentially resulting in fatigue, unconsciousness, or seizures. That’s why agencies such as Medical Detection Dogs train dogs to act as medical alert assistance dogs who tell owners when they are at risk of hypoglycemia.
What is still not known is how dogs can detect hypoglycemia even before the people themselves know. Recent research out of Cambridge University may have discovered how. Sankalpa Neupane and team measured the gases normally exhaled by diabetics and correlated those measurements with blood sugar levels. It turns out that as blood sugar gets low, we exhale more of a chemical called isoprene. Humans are not good at detecting isoprene, but dogs can smell isoprene. Thanks to these researchers, we now have a working theory that dogs detect hypoglycemia by smelling the isoprene on their owner’s breath.
Scientists are also optimistic that this breakthrough may, one day, lead to more comfortable blood sugar level monitoring. Imagine being able to use a breathalyzer instead of taking blood.
Source: Neupane S, Peverall R, Richmond G, et al. Exhaled Breath Isoprene Rises During Hypoglycemia in Type 1 Diabetes. Diabetes Care. 39 (7): e97-e98.
Thanks to Dee and Tulah Monstah for the photo of Dixie, a medical alert assistance service dog.