What if a dog could walk past a line of people and pick out the ones who unknowingly had cancer growing in their bodies? It may sound far-fetched, but with proper training dogs may be able to sniff out disease in the same way they detect drugs or bombs.

German Shepherds that had been trained for six months to smell breast cancer were 100 percent accurate during a recent test in detecting traces the disease on a piece of cloth that had merely been touched to a woman’s breast, France-based international news service AFP has reported.

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It was “an unusual, but promising, diagnostic trial,” the news service wrote. “The technique is simple, non-invasive and cheap, and may revolutionise cancer detection in countries where mammograms are hard to come by.” That could include more rural areas, where people may not get tested and treated early enough.

The group behind the project, Kdog, explains that it works because “dogs have an exceptional sense of smell — they can detect a very precise odor spectrum in minute amounts of material.” The researchers were banking on the idea that breast cancer has its own odor, one that human noses don’t smell but doggie ones do.

According to Kdog, the women involved in the trial would take a shower with odorless soap and place cloths on their breasts overnight, then in the morning send in the cloths to the lab, where scientists presented them to the German Shepherds, Thor and Nykios.

Being able to smell a disease is not a new concept. One developing technology called Na-Nose is a device that can take a breath sample from a patient and determine if the person has any of 17 different diseases, from cancer to Parkinson’s to multiple sclerosis. It does its work by looking for volatile organic compounds in the air sample, and different diseases create different combinations of those compounds that are emitted in the breath, what the researchers on that project called a “breathprint.”

According to AFP, the next step for the Thor and Nykios project is another trial with more subjects and more dogs.

“The team believes that one day dogs may be replaced by ‘sniffing’ machines, possibly armies of electronic diagnosticians dedicated to analysing samples that people far from clinics would send them by the post,” the news service said. “Other research projects are testing canines’ ability to smell different types of cancer in samples of the skin itself, blood or urine, even the air people exhale.”

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