2. Early detection of pathologies by associated odors

2.1 Olfactory diagnosis of pathologies by dogs or rats

Specially trained dogs are commonly used to detect explosives or foodstuffs by the odors emanating from them, a frequent practice particularly at airports. Squads of scent-sniffing rats are also used to screen terrain after armed conflicts for effective mine clearance, detecting unexploded anti-personnel mines. In addition to these uses, animals can also diagnose certain pathologies early, via associated odors present in urine, blood or breath. These observations may seem anecdotal. However, in traditional medical practice, body odours formed an important part of clinical observations, providing clues to help doctors make a diagnosis. Hundreds of odors from sweat, sebum, mucus from the nasal passages, throat and lungs, urine, feces...