Can dogs smell cancer?

Dogs have a very sensitive sense of smell. This can be useful in the medical world, as dogs are able to sniff out certain diseases, including cancer. Humans have put dogs’ remarkable sense of smell to use by training them to sniff out explosives and narcotics. Their powerful noses can also detect viruses, bacteria, and signs of cancer in a person’s body or bodily fluids. In this article, we look at the evidence behind dogs’ abilities to smell and identify different types of cancer, and how medical professionals can use dogs to help diagnose the condition. Can dogs smell cancer?
Dogs can detect cancer odor signatures in a person’s skin, urine, and sweat.
Research suggests that dogs can detect many types of cancers in humans. Like many other diseases, cancers leave specific traces, or odor signatures, in a person’s body and bodily secretions. Cancer cells, or healthy cells affected by cancer, produce and release these odor signatures. Depending on the type of cancer, dogs are able to detect these signatures in a person’s: skin
breath
urine
feces
sweat
Dogs can detect these odor signatures and, with training, alert people to their presence. People refer to dogs that undergo training to detect certain diseases as medical detection dogs. They detect some substances in very low concentrations, as low as parts per trillion, which makes their noses sensitive enough to detect cancer markers in a person’s breath, urine, and blood. Which types of cancer can a dog smell?
Research has shown that dogs can detect many types of cancer. For example, a case study published in BMJ Case ReportsTrusted Source describes how a 75-year-old man visited a doctor after his dog licked persistently at a lesion behind the man’s ear. The doctor performed diagnostic tests and confirmed malignant melanoma. While nobody had trained this person’s dog to specifically detect cancer, most research studies into canine cancer detection involve teaching individual dogs to sniff out specific cancers. Trained dogs are able to detect colorectal cancer from people’s breath and watery stool with high levels of accuracy, even for early-stage cancers. The presence of gut inflammation or noncancerous colorectal disease does not seem to affect dogs’ ability to detect these cancers. Dogs can also detect lung cancer from a person’s breath. One study trusted Source found that a trained dog had a very high rate of accuracy in distinguishing between the breath of people with and without lung cancer. They are also able to detect ovarian cancer from trusted Sources from blood samples and prostate cancer by sniffing a person’s urine. One study found that dogs trained only to detect breast cancer were also able to detect melanoma and lung cancer, meaning that there may be a common odor signature across different types of cancer.