The three million olfactory receptors that dogs have can be used to diagnose cancer. For comparison, man has just some 5 million olfactory cells. Daisy is a labrador that has succeeded in detecting cancer in more than 550 people so far. And she has literally saved the life of her owner. Her success rate in detecting cancer in a sample is 93 percent.

Can cancer really be detected using specially trained dogs?

Daisy was taught to sniff out cancer by her owner, Dr Claire Guest. Doctor Guest is an expert in animal behaviour and training dogs to use their keen senses for medical purposes. She trained Daisy from when she was a young puppy using urine samples from cancer patients.

Since 2002 Doctor Guest has been successfully training dogs for the professional detection of human diseases through odour. She specialises particularly in detecting cancer in samples provided by cancer patients. In 2003 she became the head of the first training programme in the world to train dogs to identify cancer using their sense of smell. She published the results of her study in a British medical journal in September 2004.

Back in 2009, after many years of intensive research, Clair was convinced that dogs could be used to detect conditions in humans. From a low blood sugar level in diabetics, to the detection of cancer cells in an otherwise healthy body. All just using the sense of smell. The part of the brain that controls scent is 40 times more powerful in dogs than it is in people, which means that dogs can detect odour with a far lower concentration in a sample.

In 2011 she was awarded an honorary doctorate in recognition of her outstanding results and contribution to the development of new approaches to detecting life-threatening illnesses and diseases.

In 2014 her dog Daisy, who is trained to detect cancer, was awarded the blue cross medal for her pioneering work in the early detection of cancer. During tests on more than 6500 samples Daisy found over 550 cases of cancer. Signal animals can detect cancer with an accuracy of up to around 93 %.

How daisy discovered cancer and saved her owner’s life

Doctor Guest actually diagnosed herself with cancer. “One afternoon I took my three dogs out for a walk. When I opened the boot of my car, the Yorkshire terrier and cocker spaniel jumped out. But Daisy the labrador refused to jump out and kept looking at me for a long time”, says Claire. “She then pushed her muzzle against my chest several times. It was really strange. Daisy is not an attack dog, but she pressed up against me again and again and bumped me hard in the chest. I told her: “Silly girl. Come on out.” And she jumped out. We went for a walk and I couldn’t stop thinking about the situation. It hard really hurt, the way she hit me with her nose.

A few days later, in the place that Daisy had kept pressing against, Clair felt a tiny little nodule or lump. “I went to the doctor and he told me that it was just a cyst in my left breast. Right where my dog has indicated.” Clair was sent for further examination. After a mammogram and a biopsy, Claire learned that she had breast cancer.

“The doctor told me that I was incredibly lucky, that my cancer was diagnosed so early. It was very deep, so by the time I myself would have noticed anything, it would have been too late. My prognosis would have been very different then.”

After having the tumour and lymph nodes removed, followed by five weeks of radiotherapy, Clair is now free of cancer. She is grateful to her dog for saving her life.

Training signal animals to detect tumours makes sense

Doctor Guest continues to conduct research into animal behaviour and training charity guide dogs for the deaf. She has joined forces with other doctors, who have helped her to gather sufficient data to enable her to publish her study, which was featured in a British medical journal in September 2004. It was the first publication in the world to conclusively show that dogs can sense cancer and that cancer emits a specific odour. Her study was revolutionary.

Despite this, Clair has faced a considerable amount of scepticism from the professional community concerning her research. Many opponents of her work were unable to imagine any practical use for her discoveries.

In order for signal animals to help out in medicine, it is not necessary for there to be a signal dog in every surgery. Dogs are actually trained in external centres and can make a diagnosis from samples sent in from doctors’ surgeries. Signal dogs do not need to be taken into the surgery.

We too are following in the footsteps of Doctor Clair Guest. Take a look at how signal animals are trained here in the Czech Republic

how signal animals are trained here in the Czech Republic

Source: medicaldetectiondogs.org.uk, telegraph.co.uk