in

Dogs’ Incredible Sense of Smell for Detecting Cancer and Other Diseases

Researchers are tapping into dogs’ uncanny sense of smell to detect diseases like cancer, malaria, and diabetes earlier and more accurately than current diagnostic tests.

Canine Diagnostics: How Dogs Detect Diseases Early | The Untapped Potential of Dog Disease Detection

Dog disease detection. None of us are any longer surprised to see dogs saving lives, searching for missing persons, helping the police in their duties, and assisting people with disabilities in their daily lives. But there is one area that is still very little explored, where our dog has not yet revealed its full potential, or rather that of its fantastic nose: that of diagnostics.

Dogs can recognise tumours.

Many of us, unfortunately, have had the unwelcome surprise of a case of cancer in the family. To date, on the ominous podium of the deadliest neoplasms are pancreatic, oesophageal and lung cancer, with a survival rate of less than 15% five years after diagnosis.

Early identification of the disease remains the most effective tool to give patients a better chance, and this is where the prodigious canine olfaction comes in. Since the 1980s, it had been hypothesised that the physiological and hormonal alterations caused by the tumour could be perceived by the noses of our four-legged friends (who are also capable of detecting much more subtle fluctuations, such as those caused by pregnancy or the various phases of the menstrual cycle in the owner). Still, in more recent times, various study programmes have confirmed this.

The studies

One of the most recent is the one initiated in 2019 by the non-profit organisation Bio-ScentDx and a group of researchers from the Lake Erie College of Osteopathic Medicine. Four Beagies were made to smell blood samples taken from lung cancer patients, and three of them could recognise the disease 96.7 per cent of the time and identify samples belonging to healthy people 97.5 per cent of the time.

An all-English study from 2021 also analysed the dia-diagnostic potential of the canine sense of smell. Another all-Italian study from 2015 examined the diagnostic potential of the canine sense of smell. In this case, the protagonists of the experiment were Liu and Zoe, two German shepherds trained at the military veterinary centre in Grosseto in collaboration with Humanitas researchers.

The subject of the research this time was prostate cancer. This type of tumour is not easy to diagnose, as its primary marker, known as PSA (prostate-specific antigen), can be hidden from currently used instrumental examinations. But this did not fool the noses of Liu and Zoe, who, out of a sample of 900 patients (360 with prostate cancer and the remaining healthy ones), were able to identify the disease by sniffing a urine sample with 98% accuracy.

The researchers aim to find out which molecule, in particular, is detected by the dogs so that it can be used to create a highly effective diagnostic kit.

Tumours, then, but not only!

Tumour molecules give off a particular odour that distinguishes them. Each type of tumour has its smell, thanks to which the dog's sense of smell can sniff out the presence of the disease.
The dog’s sense of smell cannot only detect tumours well in advance of diagnosis. Migraine, epilepsy and narcolepsy are also seen even before they arrive.

Our ‘Doctor Dogs‘ are already used to identify many other pathological conditions. Here are a few examples. A survey in The Gambia in 2018, in which several hundred school children participated, showed that dogs can distinguish the smell of asymptomatic malaria-positive children from that of non-infected children.

The dogs, trained by the NGO Medicai Detection Dogs, identified the presence of the disease, even in the as-symptoms absence, with 70% accuracy and its absence with 90% reliability: far superior to traditional diagnostic tests used by the World Health Organisation.

And that’s not all: stress markers, released in the sweat of migraine, epilepsy and narcolepsy sufferers just before a seizure, are also intercepted by the canine nose, again allowing a clinically relevant event to be anticipated.

Moreover, we have known for some time that metabolic changes such as the peaks and troughs in blood sugar levels that occur in people with diabetes (running parallel to the characteristic hyper- and hypoglycaemic crises) are perceived by specially trained dogs well in advance of various glucose monitoring instruments.

Future applications

This opens up the possibility of training dogs specifically to ‘sniff out‘ these physiological changes before they occur, thus enabling, through their warning, help to be called for through special alarm devices and the patient to be secured before a potentially dangerous crisis occurs.

Dogs’ reactions to Parkinson’s disease and breast tumours are being studied. Although screening for breast cancer is common practice, there is a substantial body of literature on dogs that have shown signs of ‘sensing’ their owner’s disease well before mammography diagnosed it.

As far as Parkinson’s disease is concerned, there are currently no laboratory tests that allow early diagnosis; however, it seems that in people who develop this disorder, sebum production increases considerably, which gives the skin a characteristic musky smell that does not escape the olfactory cells of our four-legged friends.

And that’s not all: stress markers, released in the sweat of migraine, epilepsy and narcolepsy sufferers just before a seizure, are also intercepted by the canine nose, again allowing a clinically relevant event to be anticipated.

But what makes these extraordinary perceptions possible?

According to Swedish research, dogs can sniff out GAGs (glycosaminoglycans); the polysaccharides are responsible for the elastic properties of our tendons. With disease, GAGs are altered, breaking down in the blood and urine, and it is at this stage that dogs sniff them out. Of course, GAGs are odourless for us, but dogs have more nerve connections in the olfactory area than we do, enabling them to perceive smells that do not even exist for us.

A macrosomatic animal par excellence (i.e. one that uses the sense of smell as its predominant sense), it can identify and discriminate olfactory traces up to 100,000 times more than humans!

The professional training of these ‘doctor dogs’ must be meticulous but balanced: the moments of work and rest must be well balanced to allow the dog to process what it has learnt, and the activity must always be proposed as a game, exploiting the dog’s extraordinary propensity to discover the world through its nose.

Thank you for reading the article to the end. Your reading contribution was significant to us.

Affiliate Disclosure: The Frenchie Breed website may receive a small commission from the proceeds of any product(s) sold through affiliate and direct partner links at no cost to you.

Follow Frenchie Breed on Google News

+ posts

The "Frenchie Breed" website is a blog aimed at dog owners. We regularly publish articles about our four-legged furry friends. Among the contents of our blog, you will find ample space on the latest news in the sector, with information and in-depth analysis dedicated to the world of dogs in all its forms, the latest trends and news of the moment, curious facts, events devoted to dogs, product reviews, as well as an intense activity of information regarding the health and well-being of pets.

Please Note: The articles in the 'Frenchie Breed Blog' are for information purposes only; nothing published can or should be construed as an attempt to offer professional advice or consultation with a physician, veterinary surgeon or another health professional.

Leave a Reply

What do you think?

1.1k Points
Upvote Downvote

Written by Frenchie Breed

The "Frenchie Breed" website is a blog aimed at dog owners. We regularly publish articles about our four-legged furry friends. Among the contents of our blog, you will find ample space on the latest news in the sector, with information and in-depth analysis dedicated to the world of dogs in all its forms, the latest trends and news of the moment, curious facts, events devoted to dogs, product reviews, as well as an intense activity of information regarding the health and well-being of pets.

Please Note: The articles in the 'Frenchie Breed Blog' are for information purposes only; nothing published can or should be construed as an attempt to offer professional advice or consultation with a physician, veterinary surgeon or another health professional.

Understanding Your Dog's Winter Behavioural Changes

Canine Behavioural Changes In Winter: What To Expect

Despite its tiny size, the ego of this little Mexican dog is remarkable.

Chihuahua Breed: Origin, Physical Characteristics and Temperament