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Dogs Detecting Cancer

Updated: Jul 28, 2020

Trained Dogs Can Detect Cancer with over 90% Accuracy

Trained Cancer Detection Dogs

Innovative research in training dogs to detect cancer in saliva and breath samples is proving to have an average of a more than 90% accuracy rate. While meeting resistance from conventional medicine, as new studies from different parts of the world corroborate the same effectiveness, this could be one of the most important new developments in early detection and thus possibly better medical outcomes.

Dogs sniff cancer samples. It's noninvasive, it's quick, and it's accurate.

Dogs with great noses, usually dogs with longer noses are best at this task. In some cases, they can be trained to become cancer-detecting dogs in less than six months. Only dogs with an over 85% accuracy would be considered for medical testing. The only limitation in training is the availability of "clean samples," meaning samples that aren't compromised by other illnesses or chemical interference. Dogs have and excellent sense of smell with 300 million sensors, compared with humans five million sensors. They also have a "double smelling system: that we don't have, called Jacobson's organ which allows them to be able to detect volatile organic compounds or cancer in a sample of saliva, urine or breath.

Dr. Dog -- their noses can save our lives.

Dogs are capable of early detection of prostate cancer, which can be life-saving. This video also shows how dogs can detect deadly bacteria in hospitals.

A trained cancer detection dog will sniff saliva, urine, or breath samples, and can predict not only if cancer is present, but the type of cancer with 88-98% accuracy. They can sniff a line of samples in less than a minute, and this non-invasive procedure is economical and reliable. Many trained cancer-sniffing dogs can detect not only the presence of cancer but can identify the type of cancer. While this is a new field of research, the internationally published results are impressive.

In Situ, one of the forward-thinking training organizations, has trained nine dogs who have over 98% accuracy.

Research in Europe, including England, Italy, and France is ahead in the testing of cancer detection dogs, than the US where special interest groups are resistant to this development. In England, for example, the National Health Service is investigating how dogs can detect prostate cancer with much greater accuracy then current medical methods. Dogs have tremendous abilities to detect and anticipate a variety of medical conditions.

Here is a story of Max, a dog, who was not trained specifically to detect cancer. However, when his owner got breast cancer, and his dog was signaling that something was wrong. Even though she had received two negative mammograms, the dog knew something was wrong. Fortunately, she listened to her dog, who may have saved her life. This is why it is so important to pay attention to the communication of dogs.

There are many stories of animals seeming to know when their owners are facing serious health conditions. This story on the BBC Website called “The Secret Life of Dogs” is about an English dog named Max, owned by a woman named Maureen. At age nine, Max suddenly became so despondent and listless that Maureen thought he was preparing to pass.

Max started a new behavior. He kept nudging an area around her breast, and looking forlorn. Maureen got the hint, and got a mammogram which said she had nothing wrong. But Max didn’t agree. Without any training to detect cancer, he kept trying to get Maureen’s attention, all the while acting as if he himself was quite ill. A second mammogram at a hospital also said her results were negative. But Maureen knew her dog was trying to tell her something. She got her doctor to do a biopsy. This proved she had breast cancer. When the cancerous tissue was removed, Max, the dog, was instantly back to his regular, perky, and happy self. His detection saved her life.

In england, another dog named Daisy, according to the U.K. Daily Mail website, detected early stage breast cancer in her owner, before a mammogram could confirm it was in fact cancer. Daisy went on to be trained, and in five years she has sniffed 6,000 samples of urine, and detected more than 551 cases of cancer with a diagnostic accuracy of 93 per cent.

While it is one thing for a dog to detect changes in their owner’s health, it is quite another thing for the human to correctly read the dog’s communication or alert signals – this requires that the human pay close attention to what the dog is trying to convey.

In case you think this was an isolated incident, here is another story of a puppy who detected breast cancer in his owner, even though she had had a clean mammogram six months before. The dog detected the odor of cancer in his owner. And now researchers are taking this more seriously, especially in ovarian cancer, which often goes undetected until it is too late.

In Italy, early studies show 98.1% accuracy in dogs detecting prostate cancer. While some traditional doctors are skeptical, this is still early in the process of evaluation. Dogs will not be in the doctor's office, but the samples will be sniffed in a special dog lab.

In Detroit, the firefighters got a visit from a cancer detection dog that actually sniffs people and has been tremendously accurate. The dog is able to detect EARLY WARNINGS, through sniffing inflammatory response, changes in temperature, and other early predictors.

How Canines Detect Cancer in Humans

This video from InSitu Foundation describes how they train dogs to detect even early stage cancer.

This exciting emerging field of research is teaching dogs to detect the scent of cancer among sets of samples, even without any relationship or contact with the human they came from. A new study from Italian researchers, presented in May, 2014, at the 109th Annual Scientific Meeting of the American Urological Association, in Orlando, Florida, found that specially trained dogs were able to detect prostate cancer from urine samples with 98% accuracy. “For their study, the team wanted to see whether two highly trained dogs were able to detect prostate cancer-specific volatile organic compounds (VOCs) in the urine samples of 677 participants. Of these, 320 had prostate cancer, ranging from low-risk to metastatic, and 357 were healthy controls,” as reported on the website Medical News Today.

The trained dogs work from samples of either urine, blood, tissue, or breath. “They found that the dogs were able to detect prostate cancer-specific VOCs in the urine samples with a combined accuracy of 98%. Sensitivity to the compounds was 99% accurate, while specificity was 97% accurate.”

According to an NBC News Website, “Each year 29,000 men in the US die of prostate cancer.” Current medical anal digital exams are an aid to early detection, but they are not always accurate. Specially trained dogs, on the other hand, can detect the scent of the byproducts of cancer using urine samples. They also reported that this team of two specially trained dogs was 98% accurate in their detection of cancer. “This high-level of accuracy is unheard of in traditional medical testing methods. These dogs were really able to detect these particular compounds with a high degree of accuracy,” said Dr. Stacy Loeb of New York University Medical Center, a urologist who was not involved in the study.

Alfie is another new addition to the In Situ team. He will be owned and loved by Dr. Hilary Brodie, Chair of Otolaryngolgy at University of California, Davis. Alfie is a Labradoodle (Lab/Poodle hybrid) who will also be trained to detect upper thoracic cancers, and he will be working toward advancing bio-detection by canines at UC Davis.

“These data show that analysis of volatile organic compounds in urine is a promising approach to cancer detection,” said Dr. Brian Stork, a urologist at West Shore Urology in Muskegon, Michigan, who also was not involved in the study. In the U.S. more than 230,000 men a year are diagnosed with prostate cancer. There’s a debate now over whether too many men get diagnosed with and treated for prostate cancer, when they may have a slow growing form that never would have caused them any harm.

The Bloomberg Website reported:

"In 2012, the Preventive Services Task Force, which reports on medical issues to the U.S. Congress, recommended that healthy men shouldn’t be screened for prostate cancer using PSA tests, after research showed that false positive rates of men tested may be as high as 80 percent. The PSA test measures a protein made by prostate cells called prostate-specific antigen. "

Clearly, trained canine detection, with a proven 98% accuracy rate, is better than the current medical methods being used, although as with anything new, the resistance from vested financial interest groups remains an obstacle to accepting canine cancer detection in humans.

The website Medical News Today, reporting on this story states:

"A dog has around 125 to 300 million scent glands, while a human has around 5 million scent glands. This means a dog's sense of smell is around 1,000 to 100,000 times more sensitive than a human's. While we have around 5 million olfactory cells in our noses - receptors that detect different odors - dogs have approximately 200 million."

InSitu's dog Stewie is a 5 year-old, female, Australian Shepherd. She has been one of In Situ’s best dogs, and has been trained to detect early stage lung, ovarian, and breast cancer. She was one of our star dogs in a 2012 ovarian cancer study, and she is also on Duke University’s canine team for breast cancer. Stewie has also competed in agility, obedience, and is a certified therapy dog with Pet Partners and LA Children’s Hospital, where she visits sick children. Stewie was nominated for the 2015 American Hero Dog Award, given by the American Humane Association. Stewie is a beautiful, loving, smart and talented dog, who loves her work more than anything, except the frisbee.

While dogs detecting cancer is a new field of research, it is possible that with further training the dogs can also learn to detect the differences between slow growing cancer, and dangerous cancer that requires treatment. Medical News Today further reported that:

"Dogs are now being used for detection of various cancers. One study revealed that trained detection dogs were able to detect ovarian cancer in tissue and blood samples through sniffing out volatile organic compounds (VOCs). A 2011 study conducted by researchers at UK Charity Medical Detection Dogs, found that such compounds could also be biomarkers of bladder cancer. "

Although the field of using dogs to detect cancer is new, what is significant is that different researchers, (for example, those at the University of Pennsylvania Veterinary School), using different dogs, and different methods of detection, are producing similar results of greater than 90% to 98% of accuracy, according to researchers at the InSitu Foundation. The two percent margin of error may have to do with human-error elements we have yet to define, such as the presence of other diseases in the same sample, need for more samples to better train the dogs to isolate specific scents, such as the different stages of a particular disease, and so on.

InSitu - Detecting Stage Zero Cancer and Pre-Cancer

Linus is a 3 year-old male German Shepherd who was also on death row, and adopted by In Situ Foundation. He was returned to the shelter three times by his previous owner. When he came to our ranch and got his first “job”, it literally transformed Linus’s life. Linus went from a small “jail cell” to a life of love and play. He’s happy, balanced, and well adjusted, and he’s the most loving boy around! Linus loves his work, and he’s a gem on our cancer detection team. Linus also works on the Duke team of breast cancer detection dogs.

The InSitu Foundation, founded by dog trainer Dina Zaphiris, after her mother died of breast cancer, uses breath samples to detect breast, lung, prostate, ovarian, and colon cancer. InSitu refers to the fact that the dogs are able to detect cancer at the earliest possible stage, called stage zero, before any machine or medical testing method can detect the presence of a tumor.

On InSitu’s website is an article titled: “The Diagnostic Accuracy of Canine Scent Detection in Early and Late Stage Lung and Breast Cancer” which was published in 2006, in The Medical Journal of Integrative Cancer Therapies.” Bloomberg reports that, “Her organization is in the process of submitting an FDA application for approval of a canine medical scent detection kit. In her system, patients exhale through a tube on to a cloth, which captures molecules, or VOCs, of a malignancy. Trained dogs then sniff the cloths for their presence.”

Leo is a 2 year-old, male German Shepherd, that In Situ Foundation adopted from Westside German Shepherd Rescue. Leo was on death row, and he was scheduled to be euthanized. He is a wonderful, loving, friendly and well-trained dog, and he’s very valuable to In Situ’s team. Leo is on the team of dogs working in conjunction with Duke University on a two-phase, breast cancer trial.

InSitu has taught several different breeds, and is able to train a dog who is skilled in nose work to detect cancer in six to eight weeks of training, (compared to the several years of training for Service Dogs). Based on the phenomenal success rate of dogs, researchers are working on developing a machine that can replicate a dog’s sense of smell. So far the machines do not have the high accuracy rate that dogs possess. It is hoped that in the future greater acceptance of the non-invasive, cost-effective method of training dogs to detect cancer will be more broadly accepted.

Pigeons Detect Cancer on Pathology Slides

It is not as if they are going to replace doctors, but they could become partners with traditional methods of detection. Pigeons have about 85% accuracy with detecting cancer cells.

Pigeons don't get much respect by the general public, but after watching this video, if you are not in awe of pigeons, you will be! In some cases, they are more accurate than mammograms.

Pigeons have also been trained to recognize and detect hairline fractures on x-rays. Then they alert the radiologist of the presence of a hairline fracture with an accuracy that can surpass their human medical professionals.

Genie Joseph, PhD

Director: The Human-Animal Connection


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