Dogs.. Such a small beautiful word invented by humans which also mean a persistent source coming out of depression and people use it for safety. We have plenty of reasons to love dogs. They offer us loyalty, comfort, love, companionship and so many that we can't even count them. Dogs are also used in therapy sessions as people may not like to share their real feelings with a human as they fear to be judged and to talk about their insecurities but feel much more comfortable with dogs as they would also give the patients that emotional support and would not leave in our difficult situations and this is why they are also known as a symbol of 'loyalty'.
THE SCIENCE BEHIND THE DOG'S SNIFFER
In a book "Nose of a Dog", research scientist Alexandra Horowitz notes that “most of what the dog sees and knows comes through his nose.” Depending on the breed, a dog’s nose has around 125 million to 300 million scent glands, while a human’s nose has around five million scent glands. That means that a dog’s sense of smell is around 1,000 to 100,000 times more sensitive than a humans.
Research indicates that dogs are capable of detecting tiny traces of odors created by different diseases. How tiny?
While it remains unclear what exactly makes dogs such good smellers , it is indisputable that much more of a dog’s brain is devoted to smell than it is in humans.
HOW DO DOGS BEHAVE WHEN THEY DETECT CANCER?
The ability of dogs to detect melanoma, a potentially fatal skin cancer, has been formally studied and confirmed. "LIKE MANY OTHER DISEASES, CANCER ALSO LEAVE TRACES OR ODOUR SIGNATURES". Dogs cannot detect every type of cancer but some. They can detect through the smell from odours from substances cled volatile organic compounds (VOCs).
Depending on the type of cancer, dogs are able to detect VOCs in a person’s:
skin
breath
urine
feces
sweat
Dogs can detect these odor signatures and, with training, alert people to their presence. People refer to dogs that undergo training to detect certain diseases as medical detection dogs.
Trained dogs can detect some substances in very low concentrations, as low as parts per trillion, which makes their noses sensitive enough to detect cancer markers in a person’s breath, urine, and blood.
WHICH TYPE OF CANCER CAN DOGS SMELL?
Research has shown that dogs can detect many types of cancer, such as:
melanoma
colorectal cancer
lung cancer
ovarian cancer
prostate cancer
breast cancer
For example, one case report Trusted Source describes how a 75-year-old man visited a doctor after his dog licked persistently at a lesion behind the man’s ear.
The doctor performed diagnostic tests and confirmed malignant melanoma.
Nobody had trained this person’s dog specifically to detect cancer. However, most research studies into canine cancer detection involve teaching individual dogs to sniff out specific cancers.
Scientists have found evidence that some dogs can detect colorectal cancer from people’s breath and watery stool with high levels of accuracy, even for early-stage cancers. The presence of gut inflammation or noncancerous colorectal disease does not seem to affect dogs’ ability to detect these cancers.
Dogs may also detect lung cancer from a person’s breath. One study Trusted Source found that a trained dog had a very high rate of accuracy in distinguishing between the breath of people with and without lung cancer.
In another study Trusted Source, two dogs received training for 1 year. After this, researchers presented the dogs with a number of urine samples. The dogs proved 45–73% accurate in detecting lung cancer through the samples.
Dogs have also detected Trusted Source ovarian cancer from blood samples and prostate cancer by sniffing Trusted Source a person’s urine.
In 2021, researchers reported Trusted Source that a dog trained to detect signs of breast cancer in urine was able to detect breast cancer with 100% accuracy among urine samples from 200 people. Of these, 40 had breast cancer, 182 had other cancers, and 18 had no cancer. This study has yet to be repeated with a larger population of dogs to see if the outcomes can be reproduced.
One study found that dogs trained only to detect breast cancer were also able to detect melanoma and lung cancer. This suggests there may be a common odor signature across different types of cancer.
ARE DOGS USED IN CANCER AND DIAGNOSIS?
The fact that trained dogs can detect cancer may have significant benefits for humans. Using dogs to support the detection and diagnosis of cancer is a low-risk, noninvasive method.
Medical detection dogs present few side effects and may offer advantages because they are mobile, can begin work quickly, and can trace an odor to its source.
They also have the potential for use in patient care settings or laboratories to identify cancer in tissue samples from people with suspected cancers.
Dogs’ abilities may also help with developing machines that can reliably detect odor signatures from cancer, such as Trusted Source electronic noses.
However, research is still underway and the effectiveness and reliability of canine cancer detection requires further investigation. Other areas for research include which breeds of dogs are most suited to detection and which kind of training will be most effective.
SUMMARY
Dogs have a highly developed sense of smell, and some can detect the odor signatures of various types of cancer. Dogs have also shown they can detect colon cancer, prostate cancer, breast cancer, and melanoma by sniffing people’s skin, bodily fluids, or breath.
Researchers are currently exploring the possibility of using specially trained medical detection dogs in diagnosing and tracking cancer.
Canine cancer detection is a simple, noninvasive procedure with potentially fewer side effects for people. However, further investigation is necessary to validate this method for use in clinical practice.