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 also detect
lung cancer from a person's breath.
One studyTrusted 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 cancerTrusted Source from blood samples and
prostate cancer from 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.
Can dogs smell cancer in humans? Research and diagnosis