This is awesome: 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!