A new study showed that dogs can detect not only advanced stages of cancer but early ones as well.

Scientists Tadeusz Jezierski and Michael McCulloch in California have conducted the research. They trained five household dogs to detect cancer from the breath of the cancer patients.

They included 86 cancer patients, 55 with lung cancer and 31 with breast cancer and a control sample of 83 healthy patients. The cancer patients were previously diagnosed using mammogram, or CAT scans and had not yet undergone any chemotherapy treatment.

Just by sniffing the breath of cancer participants, the trained dogs were able to recognize them with sensitivity and specificity between 88% and 97%.