Can Dogs Smell Sickness in Humans? What Science Says
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Dogs are known for their exceptional sense of smell. It is not surprising that they are used in many areas, including search and rescue, detection of illegal substances, and even medical diagnoses. But can dogs smell sickness in humans?
It is a question that has been asked for years, and in recent times, many studies have been conducted to investigate this claim. Given the studies available, we can say yes, dogs can detect various diseases in humans through smell. However, this still requires further research and evidence before dogs can be officially used in clinical practice.
In this article, we will explore the science behind the claim that dogs can detect human sickness through their sense of smell.
Dogs and Their Sensitive Sense of Smell
Dogs have a highly developed sense of smell that is far more sensitive than humans. They have over 300 million olfactory receptors in their nose, while humans only have about 6 million. This means that dogs are capable of detecting even the slightest of odors that humans are unable to sense.
When a dog inhales, the air is split into two parts: One part goes to their lungs for breathing, while the other part goes to their olfactory system for scent detection. The scent detection part consists of a complex network of nerves, receptor cells, and brain areas that work together to process the smell.
What Are Dogs Capable of Smelling?
Dogs have a remarkable ability to distinguish between different smells. They can pick up on subtle differences in scent, making them useful in various fields, such as detecting explosives, narcotics, and missing persons.
Currently, dogs’ ability to detect scents is being explored for potential applications in healthcare. Given their incredible sense, dogs should be capable of detecting chemical changes in the body that humans cannot. These chemical changes may be indicative of certain medical conditions, such as diabetes, seizures, and even cancer.
Can Dogs Smell Sickness in Humans?
It is a well-known fact that dogs can detect certain medical conditions in humans. For instance, trained dogs can alert their owners of an impending seizure by detecting changes in the body’s odor. Moreover, some dogs are trained to sniff out cancer by detecting the unique volatile organic compounds1 that cancer cells emit.
The question remains, though: Can dogs smell sickness in humans, such as the flu or a cold? There is no conclusive evidence to suggest that dogs can detect the flu or a cold in humans, most likely because nobody has trained them for this. However, some studies suggest that dogs can detect certain chemical changes in the body that are associated with sickness. Many dog owners also report that their dogs seem to “know” when they are feeling unwell.
Studies That Suggest Dogs Can Smell Diseases in Humans
Cancer
In 2006, a study was published showing that dogs are able to detect cancer from the presented breath samples. This study was later supported by another study in 2019 that showed that dogs can also detect cancer from blood samples, with up to 97% accuracy!
Parasites (Malaria)
Another study in 2019 found that dogs can detect the odor of sweat from people with malaria. The researchers trained dogs to detect the odor of socks worn by malaria-infected individuals. The dogs were able to distinguish between the socks of infected individuals and those of healthy individuals with an accuracy rate of 70%.
COVID-19
A more recent study conducted in 2020 found that dogs can detect COVID-19 in humans with an accuracy rate of up to 94%. The study involved training dogs to distinguish between the odor of sweat samples from COVID-19 patients and healthy individuals. The dogs were able to detect COVID-19 with high accuracy, even in asymptomatic individuals.
Seizures
A study investigated whether dogs could detect the odor of sweat from people with epilepsy and distinguish it from the sweat odor of people who had not had a seizure. The study provided evidence that an “epileptic seizure odor” does exist and that dogs can detect changes in the odor of people with epilepsy during seizures. This finding suggests that a canine’s exceptional sense of smell may be used as a tool to alert individuals to an impending seizure.
Diabetes
There is also evidence that suggests dogs can detect diabetes through scent detection. A survey study published in Diabetes Care in 2013 investigated whether trained dogs could accurately identify the scent of hypoglycemia, or low blood sugar, in people with type 1 diabetes.
The survey concluded that trained dogs could accurately detect hypoglycemia by scent alone and that their alerts were more reliable than current glucose-monitoring technologies. The results suggest that trained dogs could be used as an alternative or complementary tool for detecting hypoglycemia in people with type 1 diabetes.
The science behind the detection of sickness in humans by dogs is still in its early stages. While these studies confirm that dogs can detect certain chemical changes associated with sickness, more research is needed to further understand the reliability, limitations, and potential applications of these findings.
How Can Dogs Help in Detecting Various Sickness?
Despite their clinical use not being officially accepted, we know that dogs can definitively play a vital role in detecting sickness in humans. Trained dogs can be used to detect various medical conditions, such as diabetes, seizures, and cancer. They can also be used in medical facilities to screen patients for infectious diseases, such as COVID-19.
In addition, dogs can help individuals with certain medical conditions by alerting them to an impending medical emergency. For example, dogs can be trained to alert their owners to an oncoming seizure or a drop in blood sugar levels. These alerts can give the owner time to take preventive measures or seek medical attention. They can even be trained to retrieve medications and a phone to help their owners communicate—no glucose monitor can achieve that!
Final Thoughts
The evidence is clear: Dogs can be trained to smell sickness in humans, but more research is needed to fully understand the scope of their abilities. Nevertheless, their unique sense of smell makes them valuable assets in various fields, including medicine. As our understanding of dogs’ olfactory capabilities continues to grow, it is possible that our furry friends will become even more integral to our healthcare systems in the future!
Featured Image Credit: rfranca, Shutterstock
