There is a great joy when Claire Guest talks about her beloved Labrador Daisy - and a sadness too.
Joy because she has Daisy to thank for her life after she sniffed out Claire's breast cancer. Joy because this dog's incredible act firmly established her own life's work. And sadness because Claire wasn't able to save Daisy from the very disease that could have killed her.
The remarkable twist in an already miraculous story is that Claire, then 45, had established the charity, Medical Detection Dogs (MDD), just months before.
Dogs Can Sniff Out Diseases
Claire believed diseases had odours - and dogs could sniff them out. Daisy had already shown in trials that she could detect bladder cancer. That she 'warned' Claire who, as it turned out, had a very deep-seated tumour which would probably have gone unnoticed until it was too late, was astonishing.
It proved that while cancer might have the same underlying odour, there were differences that dogs could detect. Affirmation for Claire and a vital turning point for MDD.
Claire, now 59, said, "It was a very deep-seated cancer and wouldn't have been found for many years.
"I wasn't of the age to have a mammogram; I would only have found it when the lump had grown significantly and without question it could have been a very different outcome.
"She saved my life. One of the huge sadnesses for me is that this remarkable thing that she did for me, down to her good nose and the relationship we had, I was unable to do for her. She actually died of mammary tumours."
She added, "Absolutely one of the hardest things I've ever, ever had to do was put her to sleep."
Claire acknowledges that Daisy gave MDD the future she has forged since 2008 - and continues to break new ground with all the incredible dogs that have followed.
Certain Diseases Have An Odour
It also helped to - finally - silence the sceptics.
Claire said, "I was hit by all this scepticism. I was constantly the 'mad dog lady'.
"I had to persuade people that this is science, this is measurable, this is not hocus-pocus. Dogs are the world's finest bio-sensors with fluffy coats and waggy tails.
"But then to say, I'm still here because my dog told me something that I was totally unaware of. It was very powerful. I could see that we were starting to get the interest of science."
Rewind to the early 2000s; behavioural psychologist Claire's faith was born out of a colleague's experience at a previous assistance dogs charity, who went to the doctor after her Dalmatian kept sniffing and nudging a mole on her leg. She was diagnosed with a malignant melanoma.
Claire later set up MDD in 2008 with like-minded Dr John Church, who had worked in a hospital in Rwanda.
Claire said, "He believed what we were saying, that certain diseases have an odour."
And why not? A dog has 350 million receptors in their noses - 70 times more than a human.
One of charity's first five Bio Detection Dogs, Claire's Spaniel Tangle, was able to prove with the most accuracy from a tiny drop of urine if someone had bladder cancer.
Claire said, "From that point on I was sort of convinced that not only could dogs smell cancer, there must be a whole range of diseases that they could detect.
"We set up the charity because we believed that whatever dogs were trying to tell us, and whatever knowledge there was that could be applied, could save thousands - millions - of lives in the future."
Medical Alert Assistance Dogs
The charity started training canines capable of detecting hypoglycaemic attacks in Type 1 diabetes patients.
Now they have a programme of Medical Alert Assistance Dogs living with people suffering from conditions like Postural Tachycardia Syndrome (PoTS), diabetes, Addison's Disease and allergies.
Those dogs act as an early warning system, alerting owners to the need to take medication - or to put themselves into a safe position - before an episode. They have placed over 200 dogs, with more than 90 active.
They are also expanding the assistance dogs programme beyond their base in Milton Keynes, Buckinghamshire, so other parts of the UK can get local support.
And their Bio Detection Dogs could be life-enhancing - identifying incurable conditions at a pre-symptomatic stage, allowing earlier medical intervention.
Imagine being warned early about Parkinson's, prostate cancer, colorectal cancer and bacterial infections.
MDD have already proved dogs can identify E.coli, usually behind urinary tract infections in older people.
Claire said, "In the elderly population, the fear is that when they have the first fall it could lead to a change in lifestyle and independence.
"Most of those who have fallen and been admitted to NHS hospitals have a UTI, and that's what led to the fall. They can break a hip or shoulder, end up in hospital for a long time and many of them never return to complete independence.
"If we can spot UTIs early, we can get someone on the right care pathway."
Thank You Players Of People's Postcode Lottery
Players of People's Postcode Lottery have supported the charity since 2018, raising £1.7 Million to date.
Claire said, "The relationship between ourselves and players of People's Postcode Lottery is incredible. The difference it makes to our ability to plan and deliver these wonderful dogs to people who need them, and the confidence this has given us to grow and deliver around the UK has been massive. It wouldn't have happened without players supporting us."
Now, MDD's work has gone transatlantic with scientist Dr Andreas Mershin - based at MIT in Boston - working on tech that can detect disease by scent.
And it is a fitting tribute to the dog that propelled them this far, five years after her death aged 13.
That's because, in another twist of perfect fate, Dr Mershin is being helped by data from Claire's Labrador Florin - cancer sniffer extraordinaire and niece of her beloved Daisy!
Making A Difference
People's Postcode Lottery players are helping deserving causes like Medical Detection Dogs make a difference every single day. Read more about the range of Charities that our players support.