namely "medical detection dogs" (MDD) for early disease diagnosis, and "medical detection dogs" for warning patients before they develop symptoms. "medical alert/response assistance dogs". How to discover the amazing abilities of dogs? Dogs are animals that live in groups. They often act together in groups. During the process of getting along, they often observe each other's behavior or smell each other's odors to find out whether their companions' bodies are abnormal. The sensitivity of the dog's nose is very high. The main reason is that when they breathe in, the channels of inhaled and exhaled air are different, so that the inhaled odor molecules can stay in the nasal cavity, which strengthens the dog's ability to distinguish odors. This unique structure makes dog noses more sensitive than humans, so we can say this: dogs use their noses to

understand the world and transform the world into a combination of smells, just as humans use their eyes to identify objects, and form the combination of colors, shapes, and perspectives to form what we see in our eyes. world. The first dogs to be found to be sms services able to detect human disease were included in a 1989 study in The Lancet, a British medical journal. At that time, a British woman told the doctor that she wanted to remove a mole on her leg because her pet dog was very interested in the mole. Troubled her life. After the operation, the doctor was surprised by the test results. It turned out that the mole was a cancerous lesion. If it is not detected and treated early, it may be life-threatening! Since then, more and more similar cases have emerged, making researchers interested in this amazing ability of dogs.

What are they smelling? What does disease smell like? Scientists have found that dogs can only distinguish changes in the smell of volatile organic compounds (VOCs) in human urine, sweat, feces, and breathing gases. When human cells are in the process of metabolism and synthesis, hundreds of VOCs will be released continuously, and the composition of organic compounds usually represents the metabolic status of an individual. For example, when human beings breathe, air is inhaled and then goes through the lungs for gas exchange, and then exhaled to expel metabolic waste from the body. These exhaled gases contain many VOCs, and doctors can collect sample information of these VOCs to further monitor the human body. healthy.