Is It True That Dogs Can Smell Fear?

Thanks to their sensory abilities, many animals have been the subjects of many myths. Popular belief has long been that dogs can smell fear. But, is there any truth to this claim?
Is It True That Dogs Can Smell Fear?
Francisco María García

Written and verified by the lawyer Francisco María García.

Last update: 27 December, 2022

Thanks to their sensory abilities, many animals have been the subjects of different myths. Popular belief has long been that dogs can smell fear. But is there any truth to this claim?

In the past, people believed that there was only one type of intelligence and that only humans could attain it. Fortunately, the development of veterinary science demonstrates that animal instinct can represent another class of intelligence.

Through the observation of animal behavior, we can discover the truth behind many human prejudices. What’s more, modern science can show us whether or not it’s really true that dogs can smell fear.

Does fear have a scent? How can dogs perceive it?

It’s a scientifically proven fact that dogs have a much more sensitive and refined sense of smell than humans. Their olfactory abilities are even stronger than many other animals. That’s why it’s so common for canines to participate in missions like the detection of drugs, weapons, bombs and even illness. But does that mean that dogs can smell fear, too?

To offer you a response, scientists have conducted experiments to better examine dogs’ sense of smell.

Dogs and sense of smell.

Popular belief affirms that dogs and some other animals are able to tell when humans are afraid through their sense of smell. For example, this is why horses won’t allow certain individuals to mount them. In the same way, dogs may possess a similar defense mechanism when it comes to human beings.

Does fear have a smell?

If dogs can smell fear, this it must mean that the feeling of fear produces a distinct, recognizable smell. This is the only logical explanation behind the belief. But if fear has a smell, where does it come from?

The most acceptable explanation today is based on the olfactory ability to recognize the somatic indicators of fear. The feeling of fear is basically an organism’s defense mechanism. Fear allows us to be on alert against possible threats.

So then, if humans perceive a situation as dangerous, our bodies release a series of hormones to prepare us to react in the case of extreme threat. These hormones release in our blood and other body fluids like urine and sweat.

The presence of those hormones alters a person’s particular smell. And, since dogs use their sense of smell as a tool for recognition, they may react to certain strange aromas. This is the first possible explanation for why dogs can smell fear.

More symptoms that may allow dogs to sense fear

All that being said, a change in a person’s odor is not the only physical symptom of fear. Excessive sweating, increased heart rate, restlessness, and anxiety all indicate fear. Other symptoms include changes in body temperature and tone of voice, dry mouth, etc.

All of these are a body’s natural tools for self-preservation and survival.

When dogs smell fear, it’s also because their senses (especially their senses of smell and hearing) recognize these indicators. Sweat possesses a characteristic smell that dogs can sense. At the same time, dogs with a very keen ear may be able to perceive increases in heart rate. The combination of these factors may be what puts dogs on alert.

Therefore, it’s best not to force interactions with a dog if a person perceives the animal as a threat. It’s not that the dog is looking to take advantage of the situation to attack. Rather, the dog’s own survival instincts may cause it to react as a means of prevention.

Animals and natural disasters

Another curiosity based on the same logic is the claim that some animals–especially dogs–can sense natural disasters.

Dogs can smell fear.

This claim has gained strength after groups of scientists from different countries have observed alterations in the behaviors of animals weeks before natural disasters.

The bodies of animals are capable of perceiving alterations in ground and air composition.

On the one hand, gas emissions will cause an increase in the number of positive ions in the environment. This will, in turn, lead to the production of a hormone similar to adrenaline. As a result, animals become agitated and try to escape.

On the other hand, birds and mammals perceive seismic vibrations produced by the intensified movement of tectonic plates. This is the case of chimpanzees and elephants, for example.

This may explain why animals–especially dogs–become hyperactive when they sense changes in their environment: they may be sensing a natural catastrophe.

Here’s another article for you about dogs’ amazing abilities…


This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.