10 Surprising Ways Animals Use Scent to Send Messages

9. Disease Detection: Scent as a Health Indicator

It turns out that scent isn’t just a tool for communication or navigation—it can also reveal hidden signs of illness. Dogs—with their incredible noses—have been trained to detect diseases like cancer, diabetes, and infections in humans, often before medical tests can. But this ability isn’t unique to domesticated animals. In the wild, many species rely on scent to assess the health of potential mates or even rivals. By picking up on subtle chemical changes in an animal’s scent, they can avoid sick individuals and ensure they’re choosing the strongest partners. It’s a built-in survival mechanism that not only helps prevent disease from spreading but also increases the chances of passing on healthy genes.