Cancer can be a silent deadly killer.
But dozens of pet owners have revealed how their dogs were able to detect different forms of the disease before the doctors did to help save their lives, using their powerful sense of smell.
It’s estimated a dog’s sense of smell is 10,000 to 100,000 times more powerful than humans, meaning some breeds can detect a substance at a concentration of one-billionth of a teaspoon.
Their supreme sense of smell has been harnessed to detect a range of things, from detecting drugs and explosives to tracking down criminals.
Diabetic alert dogs can even sniff out changes in the blood that occur when blood sugars becomes too low or too high.
In a Quora thread posing the question ‘does cancer have an odor?’, more than 100 commenters told stories of their dogs sniffing out the disease in both humans and other canine companions.
Kim Reed, a retired accountant at American Airlines from North Carolina, said her dog helped detect her breast cancer.
She wrote: ‘I had a three-month-old lab puppy that was going to be trained as my service dog.
‘When I would hold her she insisted on facing to the right and would nudge and scratch right under my breast.’
Dozens of pet owners have revealed how their dogs and cats detected their cancer using their powerful sense of smell
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Ms Reed continued: ‘Upon examination I noticed a lump but not necessarily in the breast, just below it. I was scheduled for a routine mammogram but I called my doctor and asked about moving it up.
‘It turns out that it was cancer but would not have been found in a routine mammogram. It was at the very edge of the breast tissue and it had to be specifically addressed.’
Ms Reed said had her dog not spotted the lump below her breast, it might have ‘grown and spread.’
She says her surgeon went on to refer to her four-legged friend as her ‘wonder puppy’ and the dog remains her faithful companion more than three years on.
Jan Heaton said she had ‘always heard that animals have a sense about cancer,’ but she had ‘never experienced it’ until recently.
While walking her dog in the park, a Labrador took interest in her, sat by her side and ‘periodically nudged’ her right hand.
Ms Heaton assumed the dog was just looking for attention, but the owner then revealed that she had a special ability to ‘pick up cancer in people.’
In response, Ms Heaton revealed to the Labrador’s owner that her skin cancer had returned after 10 months in remission and she was due to undergo surgery.
The owner asked where the cancer was as the Labrador seemed focused on her right arm, and Ms Heaton confirmed that the cancer was in her upper right arm.
Similarly, Heather Gunnerson from Colorado, revealed her mom’s golden retriever helped sniff out a rare, non-cancerous tumor in her stomach.
She said she was always wary of her mom’s pooch, as he had been rescued from a ‘neglectful and abusive’ home and ‘had issues.’
But more than 20 years ago when she visited her mom, she said she was surprised when the dog approached her and would not leave her alone and started ‘constantly poking his nose’ in to her stomach.
She recalled: ‘He would smoosh his snoot into my stomach and sniff, smoosh and sniff, repeat.
‘I’d been having a lot of pain and discomfort but figured it was due to ruptured ovarian cysts to which I’m prone.’
In a Quora thread posing the question ‘does cancer have an odor?’, more than 100 commenters have offered their opinions with the majority stating ‘yes’
However, two days later, Ms Gunnerson went for a doctor’s appointment where they did ultrasounds where they found a ‘very concerning mass’ and she was in surgery the next morning.
She said the doctors found a rare, non-cancerous tumor in the lining of her abdomen.
After the mass was removed, Ms Gunnerson said her mom’s dog no longer took any interest in her.
Because of this, she concludes: ‘I think the dog absolutely could smell the tumor (or something related to it) and the lack of it once I had it removed.’
Unusually, Cris Smith said that when her mom was dying from cancer, she started having ‘hostile encounters’ with dogs, which ranged from growling to biting.
Along with cancer, Ms Smith believes canines can smell other illnesses.
Now, after being diagnosed with kidney failure herself, Ms Smith says her own dogs have started ‘acting strangely’ around her.
She explains: At first they didn’t want to take treats from my hand, which they’d done eagerly for nearly 10 years, to growling and moving away from me.
‘One day one of them bit me and broke skin (there had been snapping incidents in the recent past) but they still continued to treat my husband as they always had, with affection and enthusiasm.
‘My heart was broken over this. Then one day the dog next door rushed me and bit me. I had previously played with him and he’d always been friendly to me.
‘In retrospect I believe it was because the dogs could smell or some other way sense the disease.’
Along with dogs, some commenters have revealed how they witnessed cats harnessing their sixth sense.
Backing up the Quora claims, Cancer Council notes many studies have confirmed animals can detect cancer in the human body.
A 2021 study based out of Germany and published in the British Journal of Cancer (BJC) looked at if sniffer dogs could detect lung cancer from breath and urine samples.
After a one-year training program in a double-blind clinical trial, the dog was able to detect lung cancer using breath samples and urine samples with an overall detection rate of 98%.
The researchers said the results show how dogs could therefore be a ‘simple and non-invasive tool’ used to detect lung cancer.
Along with dogs, the Cancer Council says a large variety of animals, including rodents, insects and roundworms, have been ‘used for this purpose and have all shown their capacity to detect cancer.’
But ‘currently, the matter remains a subject of research rather than procedure.’