Why train a dog to smell Parkinson's?

Sometimes it is good to have your expectations confounded. This week I set off on a research trip for what I thought would be a fun but lightweight story about a somewhat eccentric charity that trains dogs to sniff out a range of diseases including Parkinson’s. I came away convinced I had met a very impressive medical research operation helping both patients affected by a range of disorders and scientists trying to understand them.

The first clue was arriving at the business park where Medical Detection Dogs is based to find that it was located in calm, spacious offices with a range of hi-tech equipment rather than the noisy dogs’ home I had envisaged.

There were plenty of dogs roaming around, but there was no barking or snarling - after all many of them were senior members of staff, experienced at using their extraordinary noses to sniff out. disease.

Dr Claire Guest with Dibble

It was the founder and chief executive of the charity Dr Claire Guest who immediately made me realise this is a serious business with her description of what happens when what she called a dog’s incredible bio sensor went into action:

“They draw air into the nostrils, it goes into the back of the throat to go into the olfactory epithelium. They're able to hold air in the back of the throat so it can be analysed on the special shelf they've got, and they can exhale old air through these slits at the side of the nose, at the same time as bringing new air in. So they're incredibly designed for the olfactory task.”

A behavioural psychologist withn a passionate interest in dogs and how they interact with humans, it was meeting a young woman at the animal charity where she worked which set Claire Guest on her current path. The woman had a pet dalmatian which kept licking and sniffing at a mole on her leg. Eventually she went to her GP who told her the mole was a malignant melanoma, something that could well have killed her if she had just ignored it.

After years of research Claire Guest teamed up with a surgeon to write a paper for the British Medical Journal in 2004 describing how dogs could be trained to detect cancer. The following year she launched her charity and twenty years on Medical Detection Dogs has shown that its trained animals can detect bowel and prostate cancer, Covid, urinary tract infections in care homes and now, after the results of a successful trial published earlier this month, Parkinson’s.

Now we moved to the lab to see one of the trained dogs, Peanut, in action. His trainer Mark Sommerville, who has been doing this job for 11 years, explained that the dogs were trained with pieces of cloth impregnated. with sebum - sweat, basically - collected from people with Parkinson’s. The samples are from people who have not started using medication as the aim is to learn more about people who have yet to be diagnosed.

Before Peanut was allowed into the room, Mark explained that he had put the. Parkinson’s swab in the third of four stands, the others containing swabs from people without the disease. Peanut bounded in and, while Mark stood behind a screen so as not to influence him in any way, started to make his way past the sample stands. He swiftly checked and dismissed the first two, then stopped in front of the third stand making it clear this was his choice. Mark signalled with a clicker that the test was over and rewarded Peanut with a treat.

Very impressive but, I hear you ask, what is the point? Are we really going to put trained dogs in every GP surgery to sniff out Parkinson’s? No, that is just as unlikely a scenario as Joy Milne, the woman who can smell Parkinson’s, being asked to sit in a neurologist’s office giving a second opinion on a diagnosis.

But like Joy, the Milton Keynes are contributing to a programme of research at Manchester University which is attempting to take that idea that a few humans and many dogs can smell Parkinson’s and turn it into a test which could provide early diagnosis.

“We're working to find out what it is the dogs can detect, how reliably they can detect it, how early on they can detect it,” says Claire Guest.“It's finding out how reliably Parkinson's could be detected early through a non invasive, rapid test, which would then hopefully lead to a greater understanding of the disease process.”

I was shown another room where Peanut repeated his successful detection of the Parkinson’s sample but this time with his every move being tracked in great detail by sensors. Dr Guest explained that this generated vast amounts of data which the charity handed over to scientists who are trying to create what is, in effect, an artificial nose: “The team we work with, work with sensors that mimic animal olfactory sensors.”

This collaboration with scientists trying to understand what is going on in the human brain in the early stages of Parkinson’s is partly funded by the Michael J. Fox Foundation, a measure of how seriously the work of Peanut and friends is taken.

But the Medical Detection Dogs charity has a wide range of activities. It also supplies around 200 assistance dogs to people with long-term conditions such as type 1 diabetes. The dogs can sense stress in their owners and alert them when for instance a diabetic’s blood sugar levels are too high or too low.

And Claire Guest is particularly proud of the charity’s work on detecting UTIs in care homes, something which left untreated becomes very costly both to the wellbeing of the residents and the budgets of the NHS hospitals where serious cases end up. One study showed that the use of what are known as bio detection dogs was a lot more cost effective than other methods of testing for UTIs and by providing an early alert resulted in residents recovering far more quickly. And Dr Guest points out that there’s another benefit - the residents just love having the dogs come to visit.

As one of the charity’s volunteers drove me back to the station I reflected on what I had seen - clever dogs using their noses to do vital work making people’s lives better. What a grand day out..