Do Dogs Sense Your Sickness? Unraveling The Mystery

It is a common belief among pet owners that dogs can sense if someone is sick. Although this concept might seem far-fetched to some, there are numerous accounts of people who swear that their furry friends were able to detect diseases or illnesses. In this article, we will attempt to unravel the mystery and answer the question, “do dogs sense your sickness?”

What makes people believe dogs can sense sickness?

There are numerous accounts of people who swear that their pet dogs can sense sickness, diseases, and illnesses. For instance, dogs have been observed to behave differently around their owners who show symptoms of pregnancy, low-blood sugar, Parkinson’s disease, and even cancer. So, what makes people believe that dogs can sense sickness?

The first reason is the sheer fact that dogs have a much better sense of smell than humans. They have been trained to detect various things such as drugs, bombs, and even cancer cells. So, it is not hard to imagine that they can smell certain chemical changes that occur in the body when a person is sick.

The second reason is body language. Dogs are very good at reading human body language, and they can quickly tell when their owner is feeling sad, stressed, or anxious. Changes in body language might be a significant indicator for them.

The third reason is behavioral changes. Dogs can pick up on behavioral changes that occur in someone who is sick, like a change in appetite or a more lethargic demeanor.

Evidence supporting the fact that dogs can sense sickness

A lot of scientific studies have been conducted to investigate the ability of dogs to sense sickness, and the results have been quite surprising. Here are some instances where dogs were able to sense if their owners were sick:

  • Anecdotal evidence: There are numerous anecdotal accounts of dogs detecting if their owners were sick. A woman with breast cancer, for example, reported that her pet dog kept nudging and licking the spot where the lump was located, even before the doctors confirmed the diagnosis.
  • Low blood sugar: Several studies have shown that dogs can detect changes in the blood sugar levels of people who suffer from diabetes. They are trained to alert their owners that they need to take their medication or eat something sweet to stabilize their glucose levels.
  • Seizures: Certain breeds of dogs have been trained to sense seizures in people with epilepsy before they happen. They alert their owners to lie down before the seizure occurs to avoid injury.

The science behind a dog’s ability to sense sickness

As mentioned earlier, dogs have a much better sense of smell than humans. They have up to 300 million olfactory receptors in their noses compared to just 6 million in humans. The part of the brain that processes smell is also much larger in dogs than humans. This means that dogs can pick up on scents that are undetectable to humans.

One theory is that dogs can smell the changes in the chemicals that the body produces when an individual is sick. For instance, some cancers can produce volatile organic compounds (VOCs) that aren’t present in healthy individuals. Some studies have shown that trained dogs are able to detect VOCs in urine samples from cancer patients with up to 97% accuracy.

Do all dogs have the ability to sense sickness?

While dogs, in general, have a much better sense of smell than humans, not all dogs can sense sickness. Different breeds have different levels of smell sensitivity. Breeds such as Bloodhounds, Basset Hounds, and Beagles are known for their exceptional scent tracking abilities. Other breeds such as Greyhounds have a lesser sense of smell and are better suited for other tasks.

What are the signs that my dog can sense that I’m sick?

Here are some signs that your dog might be able to sense if you are sick:

  • Your dog might become more protective and stay close to you.
  • They might start licking your skin or nudging you at a particular spot on your body.
  • Some dogs might become more anxious, and they might pant excessively or become restless.
  • If you have a service dog or a therapy dog, they might start performing their duties more frequently.

Can dogs actually detect specific illnesses?

While dogs have been trained to detect certain illnesses such as low blood sugar, seizures, and cancer, they cannot detect all illnesses. They can sense changes in your body chemistry and behavior, but they cannot diagnose an illness. If you suspect that you are sick, it is essential to visit a doctor for proper diagnosis and treatment.


In conclusion, there is a lot of anecdotal and scientific evidence supporting the fact that dogs can sense sickness, and they might even be able to detect specific illnesses like cancer. Dogs rely heavily on their sense of smell, body language, and behavioral changes in their owners to determine if something is wrong. While not all dogs might be able to sense sickness, it is still a mystery that is waiting to be unraveled.

Common Questions and Answers

  • Can dogs predict illness? While dogs can sense changes in body chemistry and behavior, they cannot predict an illness. It is always important to consult with a medical professional if you are feeling unwell.
  • Can dogs catch human illnesses? Some illnesses can be transmitted from humans to dogs, such as the common cold or the flu. However, most illnesses cannot be passed from humans to dogs or vice versa.
  • Can dogs tell if you are pregnant? Some dogs have been known to pick up on body changes that occur during pregnancy, such as hormonal changes and weight gain. However, it is always recommended to confirm a pregnancy with a medical professional.
  • Can dogs detect cancer? There is a lot of scientific evidence supporting the fact that dogs can detect certain cancers, such as lung cancer or breast cancer, by picking up on volatile organic compounds (VOCs) that are produced by cancer cells. However, more research is needed in this field.


  • “Researchers Lay Groundwork to Predict Flu Outbreaks Using Dog Sentinels.” ScienceDaily, ScienceDaily, 3 Sept. 2019,
  • Pizza, Sydney. “Can Dogs Predict Health Issues in Humans? Novant Nurse Explains.” Novant Health, 7 Sept. 2018,
  • “How Dogs Can Sense Illness in People.” The Honest Kitchen Blog – Love for Dogs and Cats, 19 Mar. 2020,

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