Dogs’ snouts may hold clue to early detection of cancer

Guide dogs have long been helping blind men and women. Picture: TSPL
Guide dogs have long been helping blind men and women. Picture: TSPL
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DOGS could help scientists develop ways to diagnose cancer by “sniffing out” the disease in sufferers, according to new research.

Experiments carried out by the Medical Detection Dogs charity showed that in some cases the animals were able to detect traces of cancer in test tubes. Another study, carried out in Germany last year, found that dogs could identify the disease on the breath of patients.

Claire Guest, chief executive of the charity, said there was a “growing body of evidence indicating there is huge potential in this work”.

Speaking on a BBC Scotland documentary to be broadcast next week, she said: “We don’t envisage in the UK that every doctor’s waiting room will have a dog sat in the corner sniffing people for cancer.

“What we envisage in the UK is that we will learn from the dogs’ ability to do this and we will, with scientists, develop new ways of diagnosing cancer early.

“But the lack of understanding of how this work could be applied in the future I think is very concerning.

“Sadly I think that some of the scepticism comes from bias against the fact it’s a dog that’s teaching you this and not a small machine.”

Dogs have already been guiding blind people for nearly a century, and man’s best friend also plays a remarkable role in assisting people suffering from other conditions ranging from epilepsy to diabetes.

Last year, a group of doctors in Stuttgart, Germany, published a report that shows dogs can sniff out lung cancer from human breath.

The dogs identified cancer in 71 per cent of the samples and correctly identified a lack of cancer in 93 per cent of clear samples.

Professor Donald Broom, emeritus professor of animal welfare at Cambridge University veterinary school said: “I’ve no doubt at all that they can detect it.

“I think that’s clear from the results we have with lung cancer – the breath of people with lung cancer – and with people with bladder cancer, that they have the ability to detect it.

“However, in all of those studies so far they are not completely reliable. You get some positives and negatives that are not positive or negative in reality. And it’s actually very difficult to train the dogs to do this at present.”

The documentary, presented by BBC Scotland reporter and guide dog user Ian Hamilton, reports that the Association for International Cancer Research, based in St Andrews, gives £9 million in research grants every year but currently none of that is spent on dogs.

Dr Helen Ribbon, head of science at the association, said: “If there is a good, large, robust trial that shows dogs can reliably detect cancer, and we’re looking at a reliability of well over 90 per cent, then I definitely think that the way forward is pinning down the chemicals involved.

“There’s a lot of anecdotal evidence that dogs can detect cancer but of course scientists don’t consider anecdotes to be good evidence.

“I think there is cynicism about the idea that you would fill hospital labs full of trained dogs, because that of course would never be practical.”

• In Dogs We Trust will be broadcast on BBC One Scotland on Monday, December 17