Chemosignaling – the Science of Canine Training

Humans have long been aware of the power of smell. It is often said that certain scents can trigger memories and emotions, both positive and negative. But did you know that our sense of smell goes beyond just detecting pleasant or unpleasant scents? In fact, our bodies produce a complex system of chemical signals, known as pheromones, that can communicate important information to others around us. This process, known as chemosignaling, has been studied extensively in animals and is now being applied to the training of service dogs to assist individuals with anxiety, depression, PTSD, seizures, and diabetes.

What is Chemosignaling?

Chemosignaling is the process of chemical communication between individuals of the same species. It involves the production and detection of chemical signals, known as pheromones, which can elicit specific behaviors or responses in the recipient. These chemical signals are often produced in specialized glands, and their release can be influenced by various factors such as age, sex, health, and emotions.

Chemosignaling in Animals

The concept of chemosignaling has been widely studied in the animal kingdom, particularly in insects and mammals. Insects, such as ants, use pheromones to mark and follow trails, while mammals, such as dogs, use them to identify individuals and establish social hierarchies. In fact, it is believed that dogs have over 220 million olfactory receptors, making their sense of smell up to 100,000 times more sensitive than that of humans. This incredible sense of smell allows them to detect and interpret chemical signals that are undetectable to us.

Chemosignaling in Humans

While the use of pheromones for communication has been extensively studied in animals, the role of chemosignaling in human behavior is still being explored. However, several studies have shown that humans do produce and respond to certain chemical signals, particularly in the context of social interactions and emotions.

For example, a study published in the journal Psychological Science found that women exposed to tears from emotional individuals showed a decrease in sexual arousal and attraction, suggesting that tears may contain chemical signals that influence human behavior. Another study published in the journal Chemical Senses found that women exposed to a male axillary (armpit) pheromone showed an increase in the hormone cortisol, which is associated with stress and anxiety.

Chemosignaling in Service Dogs

With the growing understanding of chemosignaling in humans and animals, researchers have started to explore its potential use in training service dogs. These specially trained dogs can provide support and assistance to individuals with various disabilities and conditions, including anxiety, depression, PTSD, seizures, and diabetes.

Anxiety and Depression

For individuals with anxiety and depression, having a service dog can provide much-needed emotional support and comfort. But how do these dogs know when their owners are experiencing anxiety or depression? It turns out, they can detect changes in the chemical signals released by their owners during these episodes.

A study published in the journal Frontiers in Psychology found that dogs were able to detect changes in the levels of cortisol, a hormone associated with stress, in their owners. They also showed a greater response to the sweat of their owners collected during a moment of heightened stress, compared to sweat collected during a neutral state. This suggests that dogs are able to detect and respond to the chemical signals produced by their owners during times of stress and anxiety.


Service dogs are also being trained to assist individuals with post-traumatic stress disorder (PTSD). Dogs can be trained to recognize specific cues, such as changes in breathing and heart rate, that indicate a person is experiencing a PTSD episode. They can then provide grounding techniques, such as nuzzling or licking, to help the person calm down and regain control.


Some dogs have a remarkable ability to predict and respond to seizures, even before they occur. A study published in the journal Neurology found that dogs were able to detect impending seizures in their owners with a high level of accuracy. It is believed that the dogs are responding to subtle changes in their owner’s body chemistry, such as the release of specific pheromones, that occur before a seizure. This early warning allows the owner to take necessary precautions and seek medical attention.


Similarly, dogs can also be trained to detect changes in the body chemistry of individuals with diabetes. During a drop in blood sugar levels, the body produces a chemical signal called isoprene. A study published in the journal Diabetes Care found that dogs were able to detect the presence of isoprene with a high level of accuracy and alert their owners to take necessary measures.

Training Service Dogs for Chemosignaling

The training of service dogs to respond to chemosignals involves a specific set of skills and techniques. These dogs must be able to differentiate between different chemical signals and respond only to those that are relevant to their task. One technique used is known as the “scent wheel,” where the dog is exposed to various scents and learns to identify and respond to the relevant ones.

In addition to specialized training, the success of chemosignaling in service dogs also depends on the strong bond and trust between the dog and its owner. This bond allows the dog to pick up on subtle changes in their owner’s body chemistry and respond accordingly.


The use of chemosignaling in training service dogs is a promising area of research that has the potential to change the lives of individuals with various disabilities and conditions. These remarkable dogs, with their incredible sense of smell and ability to interpret chemical signals, are providing invaluable support and assistance to their owners. As our understanding of chemosignaling continues to evolve, we can only imagine the incredible ways in which it can be applied to improve human and animal well-being.

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