Dogs accurately detect colon cancer by sniffing breath or stool samples.

Japanese researchers have confirmed that dogs are able to very accurately detect colon cancer, even at early stages.  The researchers let the dogs sniff stool or breath samples of cancer patients, normal patients and individuals with non-cancerous conditions of the colon (i.e. diverticulitis and colitis). The dogs were remarkably accurate and predicted the presence of colon cancer without being confused by other disorders or people that smoke.

While it is unlikely that dogs will begin to screen patients, their ability indicates that the presence of cancer, even early stage cancer, leads to the production of chemicals that can be detected.  The next step is to develop a mechanical detector that is as accurate as a dog.