Can Dogs Detect Illness With Their Amazing Sense of Smell?

We’ve all heard stories and anecdotes about pets who seem to be keenly aware of their human family members’ injuries and illnesses. Maybe you’ve even experienced this yourself.

When my grandmother came home from the hospital after open heart surgery, her legs were covered in stitches where the doctors removed arteries for transplant. Long before her bandages were removed or even revealed, our dog knew something wasn’t right. He would spend extra time gently guarding her legs, and seemed visibly concerned about her well-being. When the bandages came off, he would calmly nuzzle and lick her wounds. It seems completely natural for our pets to be aware of our state of health, and they clearly do their best to help out however they can when they feel that something’s wrong.

Now scientists are trying to take this ability to detect injury or illness a step further by training dogs to find cancer in humans.

Sadly, 70% of cancers are only diagnosed after they spread — and by then treatment options are limited. By utilizing dogs’ amazing sense of smell, doctors hope to detect cancers sooner, and begin treatment while there’s still time. This could mean the difference between life and death for a patient.

Researchers at University of Pennsylvania’s Working Dog Center have started training retrievers and German Shepherds to use their extremely sensitive noses to sniff out the tell-tale signs of ovarian cancer.

The training process is similar to the way police dogs are taught to recognize the scents of bombs or drugs. First, trainers take an object that is already familiar to the dog, such as a favorite toy or blanket, and then coat it with whatever substance they are being trained to detect (in this case, bits of ovarian tumors). Over time, the size of the familiar object is reduced, while the proportion of scent is increased, until eventually the object is removed altogether and only the target scent remains. Once the dogs are trained to alert to the tumor itself, they are then trained to detect blood plasma from the tumor, and eventually even the individual chemical components of ovarian plasma. When the dog can detect these trace amounts of material, it is ready for field work.

There is already solid evidence that dogs can detect illness with their incredibly potent olfactory abilities. In 2004, British scientists discovered that dogs can detect bladder cancer in a patient just by getting a whiff of their urine. There have also been cases where dogs have “predicted” seizures in epileptics before they occur.

Dogs’ astounding sense of smell is being used for all kinds of applications, most of which have started to really take off in the last decade especially. For instance, the University of Washington’s Center for Wildlife Preservation trains dogs to keep track of wildlife populations by learning the scent of their scat. They can even detect killer whale dung from the deck of a boat! By one estimate there are already over 180 applications for canine scent detection, and this is likely to expand as humans come to recognize the immense capabilities of our talented companions.

Has your dog ever seemed to know when something wasn’t right with your health, or the health of a loved one? Please, share your stories in the comments section!