It’s no big secret that dogs have an excellent sense of smell – certainly much better than our human noses.

But it might come as a surprise that a dog’s olfactory abilities are so great that he can potentially sniff out cancer in humans.

Of course, when you consider the numbers, it makes sense that a dog’s nose is capable of such a feat…

Dogs have 25 times more smell receptors than humans, boosting their smelling ability by 100,000 times. The brain of a human is dominated by the visual cortex, but the brain of a dog is controlled by the smell or olfactory cortex, which is approximately 40 times larger than that of a human. Furthermore, the olfactory bulb in a dog has a large number of smell-sensitive receptors, which range between 125 to 220 million, and it is a hundred thousand to a million times more reactive than that of humans.

OK, dogs have a great sense of smell. We get it. But how does that translate to being able to detect cancer?

How Can Dogs Sniff Out Cancer?

Studies of dogs and cancer detection are based on the fact that cancerous cells release different metabolic waste products than healthy cells in the human body. The difference of smell is so significant that the dogs are able to detect it even in the early stages of cancer. Dogs are able to identify the chemical traces in the range of parts per trillion. Some studies have confirmed the ability of trained dogs to detect the skin cancer melanoma by just sniffing the skin lesions. Furthermore, some researchers have proven that dogs can detect prostate cancer by simply smelling patients’ urine. Dogs may also be able to sniff out the presence of cancerous cells through a human’s breath.

Not only does their sense of smell make cancer detection possible, but research suggests that dogs can be trained actively to sniff out the cancer. In Berlin, a group of researchers trained some dogs to detect the presence of various types of cancer, including ovarian cancer, bowel cancer (which apparently smells different from both endometrial cancer and cervical cancer), as well as bladder cancer, skin cancer, lung cancer and prostate cancer.

Find out what’s in your dog’s food that contains cancer causing toxins . . .

The ability of dogs to detect cancer has great potential benefits. Some researchers believe the trained dogs will become integrated directly into patient care, while other researchers recommend the skills of the cancer-detecting dogs be confined to the laboratories, where the gas chromatographs could be used to isolate the specific compounds that are identified by the dogs. Recent developments in this area include a simple breathalyzer that can change color according to the compounds in the breath indicating the presence of cancer.

Still not sold on the idea? Let the research speak for itself. Here are some studies showing the great cancer-sniffing abilities of dogs: