PULLMAN, Wash. – Dogs are loyal, playful, loving and sometimes cute as a button. It’s no wonder we love them (some of us more than others, to be sure).
Dogs were likely one of the very first animals we humans domesticated. They’ve been sitting around our campfires for a very long time, indeed. We train our dogs to sit, shake and lie down.
It also could be said the dogs train us to dispense kibbles, rawhide treats and scratches behind the ears. What matters isn’t which side comes out ahead in the exchange, I like to think, but that both sides benefit from our association.
Early cancer detection
Recently, I had occasion to read aloud a news report to my “Labrador mix” as he lay stretched out near my feet one evening.
Buster Brown came from the dog pound where he was listed as a Lab mix, although in truth the vet and I agree he has so many different influences in him it’s rather misleading to name just one. Still, because he will retrieve sticks I throw into the water, I dignify his existence by thinking of him as predominately a Labrador retriever. And he’s content with that description.
The story I read aloud originated in Germany, where a study was done with dogs that have been trained to indicate when they smell chemicals emitted by cancer cells in the human body. This isn’t the first such study to be done, but it confirmed what earlier ones had shown: dogs can be good early warning detectors of malignancies within people.
Common dogs, simple training
The German study used two German shepherds (naturally), an Australian shepherd and one Labrador retriever. (Buster, of course, was pleased to hear about that fourth dog’s participation in the study.) The dogs were trained to lie down when they smelled lung cancer.
The dogs were just house-dogs, and the training didn’t go much beyond that used in typical puppy school. So it’s likely that what the four dogs could do, so could my Buster – and your Fido too.
The canines in the study were given test tubes containing people’s breath samples, both healthy subjects and those with lung cancer. The dogs had been trained to lie down when they smelled traces of lung cancer and touch the vials with their noses. About 70 percent of the time, the dogs successfully identified patients known to have lung cancer.
Specific chemicals still a mystery
The study is not the first of this type to have been done. Other studies with dogs have tested their ability to detect breast cancer, colon cancer, skin cancer and more. Some studies have had much higher detection rates than 70 percent.
Clearly dogs can tumble to just a tiny trace of chemicals associated with cancer cells. I’ve read that dogs have more neurons running from the nose to the brain than people do, and a larger proportion of the dog brain is devoted to processing information from the nose than is the case in our noggins.
The fact that dogs can smell malignancies would seem to indicate the cancers create particular chemicals that are otherwise not in our bodies. Exactly what those compounds are remains a mystery.
In other words, we can say the dogs in Germany did pretty well at detecting lung cancer, but we don’t know what chemicals in the test tube vials were the ones the dogs responded to. And, of course, the dogs can’t tell us that part of the story.
Warm and wooly science
It’s interesting to speculate why it took us so long to ask Fido’s help in cancer detection.
I think it’s partly because of the way we view science and all things medical. We think that the best scientific or medical devices will be large and expensive machines. Likely they’ll be scary too, at least if you have to spend time with one as a patient.
It’s just outside our framework of thinking to imagine that the mutt under the kitchen table at home could do as well as a chemical detector designed by an engineer and costing tens or hundreds of thousands of dollars.
As a friend of mine in graduate school used to say, “Scientific instruments should be big, noisy, scary and cold.”
Or not!
Dr. E. Kirsten Peters, a native of the rural Northwest, was trained as a geologist at Princeton and Harvard. This column is a service of the College of Agricultural, Human and Natural Resource Sciences at Washington State University. Peters can be reached at epeters@wsu.edu.