Can Dogs Smell Cancer? The Science Behind Cancer-Detecting Dogs

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can dogs smell cancerRecently researchers have been searching for the answer to an important question: can dogs smell cancer?

Dogs play an integral part in many of our lives and owning them has been shown to have huge benefits for our health. From alleviating stress to increasing physical health in areas such as heart function and overall wellbeing, it has been proven that having an animal in your life is a hugely important factor in boosting health.

Owning a pet really is a no-brainer for living a longer healthier life!

Scientists have made an amazing discovery – our canine friends may actually be able to detect cancer in patients, using their powerful sense of smell.

The Power of Dog Senses — Dogs Smell Cancer?

We know that dogs are pretty special animals – and now they have an extra talent to add to their list of awesome traits: their most powerful sense may be able to protect us from cancer.

So can dogs smell cancer? And if so, how do they do it?

Close up of a dog's nose, can dogs detect cancer

How Canine Noses Work!

A key part of the amazing discovery that scientists have made about dogs sniffing out cancer is the complex physiological way in which their noses actually work.

Canine noses are incredibly powerful, and able to detect incredibly small amounts of odors that humans noses are not. In fact, in comparison to human noses, which can detect odors at parts per million, a canine’s olfactory response can detect at parts per trillion. To put that into perspective, that’s comparable to smelling a drop of blood in two Olympic sized swimming pools!

Their amazing sense of smell is a staggering 10,000 to 100,000 stronger than our own.

This is due to the unique makeup of their noses, which contain up to 300 million scent receptors as compared to our own, which contain a paltry 6 million. Added to that, a dog’s brain proportionately has about forty times the human brain capacity devoted to analyzing smells – meaning dogs are clearly the experts in detecting scents of all kinds.

So can dogs smell cancer? Studies have shown great success in their ability to do so. But how exactly are they used to help us?

How Do Dogs Smell Cancer?

Now that you know the amazing ways in which their noses work, you may still be wondering –  how can dogs smell cancer? Trained dogs have become increasingly looked to by researchers to help to detect cancer from patient samples including those who are in the early stages of the disease, and may not be showing any symptoms yet.

These detection dogs are trained to use their astounding sense of smell to respond to urine samples, sweat samples and even blood to find common life-threatening cancers including skin cancer caused by malignant melanoma, breast cancer, prostate cancer, ovarian cancer, bladder cancer and lung cancer.

Is it An Odor They’re Sniffing Out? Truth on Cancer Body Odor

A gray dog smells a human hand, dog smells cancer in owner

Researchers agree that cancer cells release volatile organic compounds that differ from the organic compounds produced by other cells, meaning that there is a specific odor released from patients with cancer. This is how dogs are able to detect when something is not right in a sample, or even in the person themselves.

Does cancer smell?

While the smell of cancer is undetectable to a human nose, the powerful anatomy of a dog’s nose is easily able to pick up the scent of volatile organic compounds that are produced by cancerous cells as compared to normal healthy cells.

Scientists have used gas chromatography-mass spectrometry to detect cancer in exhaled breath samples with limited success. It has been shown that even in the extremely early stages of cancer, known as Stage 0, dogs are still able to distinguish the smell of cancerous cells in a patient’s breath, with an astonishing 93 percent accuracy! Can dogs smell cancer?

It seems that they can, and with amazing accuracy.

What does cancer smell like?

While we may never know what cancer actually smells like due to our sadly inadequate sense of smell, it is comforting to know that man’s best friend is able to detect this aggressive illness with their almost supernatural powers of scent deduction. However, some dog breeds have superior skills in detecting cancer as compared to others, due to their predisposition for sniffing things out.

Which dog has the best sense of smell?

All breeds have their own strengths and weaknesses, and when it comes to whether dogs can smell cancer or not, a keen sense of scent and a character that is highly responsive to training are essential.

Sniffer dogs like Labradors, Irish water spaniels, Portuguese water dogs and Golden retrievers are all breeds that have all shown excellent capacity in the ability to sniff out cancer.

Dog breeds that don’t smell cancer – Which Dogs Have A Poor Sense of Smell

While these breeds are top of the class when it comes to scent-detecting, others are not so olfactory gifted. Dogs such as Pugs and Shar Pei have many endearing traits, however reliably sniffing things out is not one of them.

So can dogs smell cancer that have smaller snouts?

Generally not, due to their flat nose anatomy which limits their sniffing power. If you want a dog that has the potential to keep you safe from this aggressive disease, choose another breed like a Labrador retriever.

Pawesome Stories—Dogs Smell Cancer in Owner!

There have been some seriously amazing cases in which owners have been spared the heartbreak of finding cancer too late through early detection, thanks to their amazing pooches.

Actress Shannon Doherty was thankful for her trusty canine companion Bowie the German Shepherd for making her recovery from breast cancer possible. Doherty notes that Bowie alerted her to the breast cancer well before she herself noticed, making it possible to treat it in the early stages and make a full recovery.

Another astonishing tale is that of Anne Wills in Baltimore, whose German Shepherd-Labrador mix Heidi managed to sniff out her lung cancer well before she had any clue that it was there. Heidi, a trained search, and rescue dog began burying her nose into Ann’s chest and pawing at her anxiously. After getting the all-clear from the Vet on Heidi’s health, Ann decided to get checked out herself and was shocked to find that she had numerous tumors growing in her lungs, and was in the early stages of lung cancer.

Cancer-detecting dogs—What Science Says…

So what do Scientists say? Can dogs smell cancer?

Clearly, researchers and owners alike have had astounding results using man’s best friend to assist in finding cancer, and studies have shown that early detection could lead to a huge increase in the five-year survival rate from cancer.  However, securing funding to continue research into using dogs who can smell cancer has been difficult due to the logistical challenges it presents.

Why Don’t Doctors Use Cancer Sniffing Dogs

Because of this lack of funding for further developing detecting dogs, it is rare to find doctors that currently use medical detection dogs on patients in a clinical context to detect cancer. Hopefully, in the future, this will change and we can harness the amazing skills of our four-legged friends in the fight against cancer.

Can Dogs Smell Cancer? Here’s What Science Concludes!

So can dogs smell cancer?

Well, we know that dogs of all shapes sizes provide an amazing array of health benefits to their owners overall. Added to this, with future testing and scientific research, dogs look set to help us in the fight against cancer. Now, more than ever is a great time to have a canine pal in your life!


Common Questions on Can Dog Smell Cancer

Why can’t humans smell cancer?

Can dogs smell cancer that have smaller snouts?

My dog keeps sniffing me. Can I have my dog trained to detect health issues?

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