This is mind-boggling: we are aware that dogs know when we are sick- but they can even detect cancer! How? From biochemistry- “Volatile organic compounds potentially diagnostic of cancer, such as alkanes, methylated alkanes, aromatic compounds, and benzene derivatives, have been identified using gas chromatography/mass spectroscopy (GCMS) in the exhaled breath of patients with lung and breast cancers.”

These alkanes arise from oxidative stress- i.e. oxidation of the high energy fatty acids yields alkanes that can be detected in a patient’s breath. The really amazing thing is that the dog can detect compounds in parts per trillion– something our modern day breathlyzers still strive to obtain!

Diagnostic Accuracy of Canine Scent Detection in Early- and Late-Stage Lung and Breast Cancers

By Raja Selvakumar, MIT