Trainer Claire Guest and sniffer dog.
The quest to see if dogs could find cancer started with a Letter to the Editor in The Lancet, the highly respected independent British medical journal, back in 1989. The headline read: "Sniffer Dogs in the Melanoma Clinic?"
Two London dermatologists wrote about a case in which a patient had been sent to them by her dog. According to the letter, the woman had a dark spot on her upper leg that her doctor said was a mole, a small, slightly raised blemish on the skin, made dark by a high concentration of melanin. Purely a cosmetic matter, and not worth removing.
The woman was content with that diagnosis. But her dog was not. Her dog, a half Border Collie, half Doberman Pinscher would not stop sniffing the mole on her leg. She would push her nose into her skirt or pants, and sniff heavily at the spot, always interrupting and bothering her. No matter how many times she ordered her dog to stop, the canine kept coming back. At first, she laid the whole thing off to an obnoxious dog and her own bad dog training.
Then came the startling moment one summer day, when she decided to work in her garden in shorts. This meant the mole was exposed. Her dog pounced on her and nipped at the mole, trying to bite it off. She had to push her strongly to get her away. That shocked her. Her dog had never attacked or bitten her before. In reconsidering the incident, the woman realized that she had other moles on her body, but the dog completely ignored these. Why did her dog show such fervent interest in only this mole? Why would she act so strangely?
Maybe something else was wrong. She insisted on being referred to a dermatological specialist. During her examination, the doctors excised the mole and sent it to the lab for biopsy. The results came back, “Positive.” The mole was cancerous. It was a malignant melanoma, measuring 1.86 in thickness, a deadly form of skin cancer, which could have spread rapidly and killed her if she had not taken action to stop it.
"This dog may have saved her owner’s life by prompting her to seek treatment when the lesion was still at a thin and curable stage," wrote the researchers. Drs. H. Williams and A. Pembroke. Their conclusion was that her cancer must have had a scent that her dog identified as harmful to its owner. The doctors thought that studies should be done to confirm this.
For ten years, no studies were done, until a Florida dermatologist, Dr. Armand Cognetta, designed a trial with his skin cancer patients and a trained police detection dog. Publicity about his work prompted a British physician, Dr. Church, to find out if dogs could detect prostate cancer in urine samples. They could. Dr. Church’s study was featured on CBS 60 Minutes and in many news stories. Dr. Church wrote in a letter to The Lancet, Volume 358, Number 9285, 15 September 2001, “We report a man aged 66 years, who developed a patch of eczema on the outer side of his left thigh. It grew slowly, over 18 years, to about 1–2 cm in diameter. When dry, the lesion would become scabby, and it caused occasional itching. It was treated with several topical agents, including steroids and antifungals, without effect.
“A pet Labrador called Parker came to the home in 1994. About 2 years ago, the dog began to persistently push his nose against his owner's trouser leg, sniffing the lesion beneath it. This prompted the patient to return to his family physician for review. In September 2000, the lesion was excised. Histological assessment of the lesion showed it to be a basal cell carcinoma that had been fully excised. Since excision of the lesion, Parker has shown no further interest in the area.
“With these two patients, the dogs could smell the lesions through clothing, and showed no further interest once the lesions had been excised. The combination of pets contributing to preventing morbidity and possible mortality in their owners has predictably generated much media interest.
“Although all these data are anecdotal, we believe that the phenomenon of some dogs seeming able to detect unique odours of certain skin cancers worthy of investigation in rigorously controlled experiments. Whether they can detect odours associated with other specific diseases such as tuberculosis or Ebola virus should also be investigated to aid early detection.”
Dr Church still works in the field of finding ways to use canines to find cancer. His dog trainer is Claire Guest, whose photo appears here with one of her sniffer dogs.
It has been proven in three different trials that dogs are able to find skin, prostate, breast and lung cancer in urine or breath samples or on a person’s skin significantly better than any known method, better than the latest CAT, PET, and MRI scanners, better than chest x-rays and sputum cytology.
The breed of dog doesn’t matter. The stage of cancer doesn’t matter. The dogs picked it up, whether the patient was barely in Stage 1 or had progressed to invasive, metastasis Stage 4. Early detection of cancer is a matter of life or death. We have this terrific resource right at our feet, able and willing to help us stay healthy. Not enough is being done to make use of this incredible asset.
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