Medical alert dogs can be used to monitor people with diabetes and warn when they are about to suffer a hypoglycaemic attack (a time when their blood sugar drops to levels which are potentially dangerous). Low blood sugar produces a distinctive smell, which these dogs are trained to detect and react to. They can then summon help, or fetch vital supplies for their owners. More information about these dogs can be found here.
Interestingly a number of pet owners have noted that their pets, which have never been trained to do so, will behave differently when the owners are having a hypoglycaemic attack. In some cases, the owners were asleep and the animals have actually woken them up!
Dogs may be able to detect problems in people with Addisons Disease; a serious condition which can cause collapse, fits and severe pain in sufferers. Cardiff University are currently involved in research into exactly what these dogs are smelling.
It seems that dogs can also be trained to detect certain types of cancer, so jokes about a 'lab' test aren't wide of the mark! There is research going on about this at the moment, but more details can be found here.
Sniffer dogs have been used for years to detect drugs, explosives and chemicals, but they're now being used to sniff out bed bugs as well. It's amazing what a dog's nose can find! Perhaps one day soon all doctors' surgeries will have a dog in the corner of the waiting room to tell the doctor what's wrong with you.
