8 Surprising Things Your Dog Can Sense

Erika Lessa, CBST, CDBT, CDBC, CPDT-KA, Fear-Free Certified

Erika Lessa, CBST, CDBT, CDBC, CPDT-KA, Fear-Free Certified

Published Sep. 29, 2023
A Golden Retriever smiles with their pet parent.

Dogs experience the world differently from their human counterparts.

They have heightened physical senses and are aware of things we aren’t.

Dogs can detect emotion, physiological changes (changes in the functioning of the body), illness, and environmental events, such as weather. This sensitivity is connected to their ability to see, smell, hear, and feel.

They see fewer colors because of color blindness, and they see in higher contrast. This provides better night vision and the ability to track movement. A dog’s peripheral vision is wider, but they see less detail.

There’s no contest when comparing a dog’s sense of smell to their human’s. A dog has about 300 million scent receptors compared with a human’s 6 million.

A pup’s hearing also differs from ours. Dogs’ ears are built for hearing at higher frequencies than a human, but they don’t recognize changes in pitch as well as we do. In fact, there are many other differences between dog and human hearing.

A dog’s fur and skin help them feel and process interactions with other animals, including humans. Pressure from a puppy playmate’s teeth can help communicate a need for less intense play.

Given all of their incredible senses, dogs possess the ability to sense things about the world that may surprise you. 

1. Can Dogs Sense Your Mood?

You may wonder if your dog can sense when you’re sad or upset. Sadness, distress, anxiety, and anger are emotions, which trigger physiological responses in us.

This can change our speech patterns, movements, posture, and smell. Since a dog’s senses are so heightened, they can detect these signals and be able to understand what happens next.

For example, if you come home smiling and open your arms to your pup, they know you’re happy. They prance around and lean in for petting.

They may even grab a toy because when you display this behavior, play typically comes next. Alternatively, if you come home angry, or quiet—going straight to your bedroom—your pup will know to steer clear.

A human’s stress and anxiety are contagious to their dog. Dogs living with people who are chronically stressed are negatively affected in the long-term.

This study captured emotional mirroring and the synchronization of stress levels of dogs with their pet parents.

2. Can Dogs Sense a Pregnancy?

Though there’s no research confirming a dog’s ability to detect pregnancy, there are many stories of dogs changing their behavior when pet parent(s) become human parents.

Given a dog’s ability to smell hormones and pheromones (a chemical, such as a scent, that signals behaviors like mating), it's likely that they can sense pregnancy.

3. Can Dogs Sense Fear?

A dog is sensitive to fear in humans.

When a dog perceives fear in a person through smell, body language, or facial expressions, it can result in behavior mirroring.

This means a dog will show fear-based reactions in response to being exposed to a fearful human.

Depending on the intensity of fear, this interaction may activate a dog’s fight or flight response. Responses can range from avoidant behaviors to reactive ones.

If your dog deals with fear by running away (flight) or by biting (fight), it may be triggered by humans feeling tense, anxious, or afraid.

One study examined dogs’ behavioral responses to a stranger after exposure to sweat samples—one collected from a happy human, the other collected from a frightened human.

Overall, the dogs exhibited more social behaviors toward a neutral stranger after experiencing the “happy” sample and more avoidance after the “fear” sample.

4. Can Dogs Sense a Negative Person?

Because negativity is more of an attitude than an emotion, it may have less impact on a dog. That said, if negativity causes stress and anxiety in a person, emotion and mood come back into the mix.

When this happens, their dog could be affected.

A negative person who is emotionally unpredictable has a unique chemosignal that dogs can detect. If those scents predict explosive or dangerous behavior, a dog learns to anticipate unsafe surroundings.  

5. Can Dogs Sense Illness?

Dogs’ ability to smell illnesses has been well documented.

Typically, the biggest indicator of illness is through odor. Dogs can detect metabolic changes in our breath and through our skin.

Most recently, a test was studied on dogs’ ability to detect COVID-19. Overall, the average rate of successful detection was 94%.

6. Can Dogs Sense When Someone Is Having a Seizure Or About To Have One?

Seizures cause changes in a person’s physical appearance and facial expressions, thus alerting their pup that something isn’t right.

Pet parents who experience seizures can train their pups to help them. However, not all dogs will alert a person of an impending event even if they can sense it.

7. Can Dogs Sense Cancer or Diabetes?

Research has been conducted to determine whether dogs can detect cancer or diabetes.

In samples including human tissue for cancer and exhaled breath for diabetes, dogs were able to sniff out infected samples and detect hypoglycemia (low blood sugar) in those who have diabetes.

Particularly, dogs seem to notice the presence of melanoma, a form of skin cancer, in humans.

Some untrained pups have repeatedly sniffed at a spot on the skin of a pet parent diagnosed with the disease.

8. Can Dogs Sense the Weather?

Along with thunder and lightning, storms cause changes in barometric pressure (amount of air pressure in the atmosphere) and electrostatic charge (static electricity).

When air pressure drops, scent moves down, collecting at ground level.

This alerts a dog to changes in weather conditions. Static electricity builds up in a pup’s fur and creates small shocks as they move.

Dogs are highly gifted companions with a heightened sense of the world around us. If you’re not sure how you’re feeling or feel as though something is off around you, watch your dog. They may be able to give you further insight.

Featured Image: Stock.adobe.com/trofalena


Horowitz, A. Inside of a dog: What dogs see, smell, and know. Buddhi Dharma University, Indonesia. 2009.


Erika Lessa, CBST, CDBT, CDBC, CPDT-KA, Fear-Free Certified


Erika Lessa, CBST, CDBT, CDBC, CPDT-KA, Fear-Free Certified

Professional Trainer

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