A Diabetic Alert Dog (DAD), also called hypoglycemia alert dogs, has been especially trained to detect abnormal glucose levels in a human and gives a specific signal to that persons family or partner (signals can include barking or licking the support member), who once alerted can check on the child and treat appropriately. Some dogs can detect dangerous drops in blood sugar levels, while other seem to be able to detect high blood sugar.
In normal humans, blood glucose levels are maintained within strict limits by insulin, which is secreted when insulin rises above about 90 mg/dl, and by glucagon which is released when glucose levels drop to low. If you want to learn more, read How the Body Regulates Blood Sugar, and How Insulin Works.
Animals have been used for some time to detect drugs and explosives at airports and on police raids, so using them to help humans in the fight against diabetes is a sensible progression. Dogs are highly trainable and their extreme loyalty to their owners make them the perfect partner for anyone needing constant, 24 hour attention. A major problem is trying to find enough of the animals to fill the demand, since they are very expensive to train.
These types of service dogs can be especially important when a household is sleeping as any problems will not be detected for potentially hours. They can sleep by the bed of a diabetic, sniffing throughout the night to detect problem levels of blood glucose and offer a medical alert when a problem occurs.
There are a few organizations that specialize in the training of this type of dog, such as Dogs4Diabetics, a non-profit organization that provides these canines to type 1 diabetic children and adults, with both training as well as placement of the animals and a follow-up service to make sure things are working out as planned. They are trained to identify subtle scent changes (that humans cannot detect) that that occur in the human body when problems occur and then to respond with a trained signal, alerting another human so that action can be taken.
Another organization is All Purpose Canines, who have a number of professional services and programs involving dogs. They have successfully shown that they can be used to detect sugar levels in the blood. Unfortunately, according to their website, they are not accepting any new applications at this time, which I assume is because of the costs involved – specialist trainers, after placement costs etc. However, a case study on their site shows the amazing story of “Boomer”, a German Shepherd/Lab mix who is an alert dog for a lad named Ryan. Boomer was tested and certified in June 2004 by All Purpose Canines, and has been Ryan's constant companion since that time.
Another organization is Heaven Scent Paws, whose dogs are trained to detect both low (hypoglycemia) as well as high (hyperglycemia) levels in the diabetic, and then alert the “support team” who could be parents, spouse or partner.
There is no doubt that this type of dog can assist relatives of a diabetic sufferer in helping monitor the situation 24/7. However, just how accurate this is as a detection method remains to be seen, and putting too much faith in these extraordinary pets may not be wise. Those owners who have been lucky enough to get a diabetic alert dog does have that extra sense of security though.