Here’s What a Diabetes Dog Senses When Her Human’s Blood Sugar Is Too Low

The researchers, who published their findings in the American Diabetes Association journal Diabetes Care, believe the dogs smell a common natural chemical found in exhaled human breath called isoprene.1
According to study co-author Dr. Mark Evans of Addenbrooke’s Hospital, University of Cambridge:

"Isoprene is one of the commonest natural chemicals that we find in human breath, but we know surprisingly little about where it comes from. We suspect it's a by-product of the production of cholesterol, but it isn't clear why levels of the chemical rise when patients get very low blood sugar.”2
The study involved eight female volunteers with type 1 diabetes. In a carefully controlled setting, the researchers lowered their blood sugar levels, and used special equipment to detect specific chemicals in their breath as they exhaled.
The scientists discovered that isoprene levels were significantly elevated while the women were experiencing hypoglycemia (critically low blood sugar levels). In some of the women, the isoprene level almost doubled.
Humans are unaware of the odor of isoprene, but dogs, with their keen sense of smell, can pick it up.
The researchers hope their study results can be used to develop new tests for detecting hypoglycemia, and reduce the risk of potentially life-threatening complications for people with diabetes.
Two Levels of Diabetes Service Dogs

As all of us with canine companions know, dogs go through life nose-first. Their sense of smell is astounding. Dogs can pick up odors at around one part per trillion, which for humans would be the equivalent of smelling a teaspoon of sugar in two Olympic-sized swimming pools.3
It is their sense of smell that makes certain types of working and medical detection dogs invaluable. Diabetes service dogs are trained to know when their owners’ blood sugar level is dropping or too low (based, as we now know, on the amount of isoprene on their breath), and to alert them by performing a specific behavior.
There are actually two different types of diabetes service dogs. There are medical response dogs, and diabetic alert dogs. Medical response dogs are trained to alert their owners once they show symptoms of low blood sugar.
Diabetic alert dogs, on the other hand, are trained to pick up changes in their owners’ blood chemistry, and then alert either their owners or caregivers to take action. Typically, there is a 15 to 30 minute window in which to treat a low blood sugar situation before the person starts to experience symptoms.
How Diabetes Service Dogs Help Their Owners

In case you’re wondering how a diabetes service dog alerts his owner, there are a number of behaviors they might be trained to perform, for example:

  • Jumping up and putting his paws on his owner’s shoulders
  • Touching his owner with his nose
  • Sitting and staring at his owner
  • Holding a small, soft toy in his mouth that is always hanging from his collar

The dogs might also be trained in other assistance behaviors, including getting the attention of another family member if his owner needs help; bringing objects to his owner (e.g., medications); fetching the owner’s cell phone; and even dialing 911 himself, using a special device.
Diabetes Service Dog Breeds and Associated Costs

The most common types of diabetic alert dogs include Golden and Labrador Retrievers, Poodles and mixed sporting breeds. The dogs are usually 1 to 2 years old when they’re placed into service with their owners.
The most highly trained dogs are bred for the work, and socialized and trained until they’re 18 months old, at which time they begin their formal service training. It takes another six to 12 months to get the dog ready to go into service. Part of that training involves preparing the dog and his new owner to work successfully as a team.
As you might guess, training a diabetes service dog is expensive. According to Dogs4Diabetics, the dogs themselves are valued at $15,000 before training. The cost of training the dog and the dog-owner team is about $20,000, for a total of about $35,000.
The only cost to the owner to acquire a service dog is a $50 application fee and $100 for training materials.4 After the dog is placed, the owner becomes responsible for all dog care costs, and must maintain pet health insurance to cover extraordinary expenses.