Can dogs smell fear?


It is often said that dogs smell fear of humans and it seems that there may be some truth, not because fear can be smelled, but because of a series of behavioral and biological factors that can give us away when we are afraid. Let's learn more about this interesting topic.

Delving into a most interesting topic

When we talk about animals of the same species, they can detect the pheromones of their peers, and capture them with their vomeronasal organ. These types of pheromones act when there is fear, aggression, etc.

The pheromones each species has specifically and are worth to know the status of an individual, sex, state of the cycle in which the female is and more useful information for the species, but not for others. Men do not have the ability to emit or receive pheromones, because we do not have the organs responsible for detecting them.

The fact is that dogs smell intensely when some substances are released with the sweat of our skin. They even try to ride women when they are ovulating and there have been cases of dogs that act differently when their owners are pregnant.

Though Dogs cannot detect our pheromones because they do not exist if they are able to detect changes at the hormonal level and the changes at the level of behavior that humans emit when we feel fear.

Therefore, the cause does not seem to be the ability to smell the rise of adrenaline, because it circulates internally and odorlessly through the body, but if they indirectly capture the different smell that comes from the perspiration of our skin, That is when these hormones act.

The smell and the fear

The smell becomes concentrated and identified in moments of fear where the sweat is of great intensity, all coupled with an insecure behavior that are large claims that are alert for a dog that happens to feel insecure.

When a person for whatever reason gets scared and makes hesitant movements, he departs from the animal, caresses him suspiciously and fear causes him to look directly and intensely at his eyes, the dog feels like we say threatened and you may have an aggressive response with us.

You should know that, really, when a dog attacks someone who approaches him with fear, it is because the dog is afraid of someone else's fear.

This popular belief is deeply rooted, but what is really in it? Although dogs have one of the best smell present in nature, are they really able to smell something like fear?

Surely you've ever heard the phrase "be careful when approaching dogs, they smell fear." This popular belief is deeply rooted, but what is really in it? Although dogs have one of the best smell in nature, are they really able to smell fear?

Experts argue that dogs, rather than "smell," intuit and perceive things because of our behavior. In this sense, two factors must be taken into account: our hormones and our body language.

Our hormones

The great smell of dogs allows them to follow a long distance smell trail. If they are well trained they are able to detect dangerous or illegal substances, and even find people under rubble after a landslide. In the same way, when it is said that a dog "smells fear", what the animal really smells is our body odor. Thanks to this smell, dogs are able to differentiate us from other people, to detect our state of health, and they can even intuit when a woman is in the ovulation cycle. This is because they detect significant hormonal changes.

When we feel fear, stress, anxiety or excitement, we suffer changes in our levels of adrenaline or endorphins, and that is precisely what canines detect. They are able to smell through our bodily luids, such as sweat, tears, blood or urine.

Despite all this, studies have failed to determine conclusively whether dogs can detect slight hormonal changes through the smell. Some experts argue that for a dog to be able to detect such minimal changes it should be very close to the person, and even need to stick the snout to its skin. Another influencing factor is the characteristics of each dog and its olfactory abilities, which may differ greatly from one dog to another. Therefore, at the moment it cannot be said that a dog is able to detect your fear through smell. On the contrary, what gives you away is your behavior.

Our body language

Dogs can interpret the behavior of other animals or people due to their body language. Although they cannot smell fear, they detect alertness from a distance. If we are on alert, the dog can interpret that we can try to attack him, which is why he can growl or attack before being attacked, which is why people are often told not to approach a dog they don't know if they have fear.

Therefore, in response to the question of whether dogs are able to smell fear, although it is clear that they can smell hormonal changes it is not proven that they can perceive such small changes. What really confirms that you are scared is your body language if you move with tense movements or are on alert.


Good article, but I would like to understand something that happens with one of my dogs that this seems not to explain. He says "think of someone curious ..." But this dog with me lets me pet him with all confidence, and practically all other people, live in this house or not, usually approaching to receive caresses but as soon as they caress it he gets tense and growls like to attack them. Is it that my dog ​​is crazy and trusts only me? I find no explanation and I have tried to trust those around me too but nobody manages to caress it without growling. I hope you can help me, I always thought that some expert like the one you mentioned, Cesar Millan could only help us, and you seem to have great knowledge, I hope for an answer. From already thank you very much!

Hi Leandro, so in the distance it is very difficult to know. For some reason your dog is not that it smells fear, it seems that it is quite AFRAID himself and as you say, he only trusts you completely. It's not that he's crazy, it's because of something that happened to him he has insecurity. When an animal or person is mido, it becomes defensive, tries to seem "unpleasant" or intimidating so that others do not get too close. Did something bad as a puppy or young man happen to you? (Maybe they abandoned him or someone hit him). Just the one you mention, Cesar Millán says that the most difficult cases are not aggressive dogs, they are scary dogs, because you have to gradually return confidence to a being who has lost it (and that is difficult, also with humans ).

I would tell you to try something that can help. They are Bach flowers, which just serve for emotional problems. There are two or three flowers (like mimulos, rock rose or aspen) that just treat fear. It is a cheap solution and is very easy to apply. Look at this post >>

Martha Victorio says

Hello, something like this happens with my dog ​​(akita), everyone can pet him, he does not behave aggressively, but with children he is different, even to my son who was already very fond of him, I growl at him and not only that but he throws the bite That makes children, it is as if he would not like children to caress him although many children have caressed him, just those who have taken longer to do so. That day I threw the bite at my son he already had time hugging and caressing him, he had even kissed him, when I try to give him another he attacked him and I don't know if I should get rid of the dog😥 We have half a year with him and we have taken so much honey 😩😥

Testing his nose

D’Aniello and his colleagues tested whether dogs could smell human emotions just by using their sense of smell. First, human volunteers watched videos designed to cause fear or happiness, or a neutral response, and the team collected samples of his sweat.

Next, the researchers presented these samples of smell to domestic dogs and monitored the dogs' behavior and heart rate.

Dogs exposed to the smells of fear showed more signs of stress than those exposed to happy or neutral odors. They also had higher heart rates, sought more peace of mind from their owners and carried out less social contact with strangers.

We already knew that fear produces chemical signals and changes in body odor, as does happiness. What was ignored is that dogs were also able to interpret them unconsciously, just as humans do.

With 220 million olfactory cells (humans only have 5 million), the dog's smell is 4 times better than the best of the smell detecting machines. They can even smell cancer, as he explains John Lloyd in his book The little big book of ignorance (animal):

California doctors have discovered that Portuguese farmers and water dogs are able to detect lung and breast cancer more accurately than more advanced tests, such as mammograms and CT scans. Dogs correctly identified 99% of lung cancers and 88% of breast cancers just by smelling the breath of the sick.

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