While this evidence is anecdotal, the idea a dog’s super-sensitive nose could detect cancer is not that far-fetched.
A 2004 study in the British Medical Journal (BMJ) explained: “Tumours produce volatile organic compounds, which are released into the atmosphere through, for example, breath and sweat.
“Some of these volatile organic compounds are likely to have distinctive odours; even when present in minute quantities, they could be detectable by dogs, with their exceptional olfactory acuity.”
This study was the first to evaluate how well dogs could detect bladder cancer, and found the dogs correctly identified bladder cancer from a urine sample 41 percent of the time.