The ability of dogs to detect cancer in humans by scent made news again in 2005. A leading medical journal in Britain published the results of a formal study demonstrating that dogs can be trained to identify bladder cancer. The overall average success of the dogs was 41 percent, higher than state-of-the-art x-ray and CAT scan machines.

The dogs in the British study did not have previous training for scent work, and were trained by Andy Cook and Claire Guest, both of Hearing Dogs for Deaf People in Saunderton, England. The trainers are continuing to refine the training methods. It seems that a variety of scent-detection training methods have been successfully used to train dogs for detecting cancer.

Scientists tend to choose sides as to whether they believe dogs can detect such scents, and the division runs along the lines of those who have worked in depth with dogs and those who have not. Experience teaches humans things about dog abilities that science simply does not understand.

An anomaly in the British study on bladder cancer represents a good example. The dogs kept indicating a sample the scientists said was not cancerous. Finally someone had that patient evaluated more thoroughly, and cancer was found.

Anecdotal Reports

The interest in training dogs to detect cancer has largely been fueled by anecdotes--stories of dogs alerting their owners to something not right--that turned out to be cancer. Gill Lacey’s Dalmatian Trudi alerted him to a malignant melanoma on his leg 25 years ago. He understandably believes she saved his life.

Researcher Dr. John Church was inspired by a half dozen local cases where people had cancer diagnosed after their pet dogs became a little obsessed with a part of the person’s body. Such stories have caused researchers and trainers to look at this ability more closely and now to prove scientifically that dogs have it.

Special Dogs

George the Standard Schnauzer and his handler Duane Pickel had previously trained to find explosives. Their work with Tallahassee, Florida, dermatologist Dr. Armand Cognetta in detecting melanomas gained well-deserved attention. Other trainers have also had success with methods similar to those used to train dogs for such jobs as explosives and drug detection.

Shing Ling-hua was an apricot Standard Poodle who worked as a therapy dog in the Pine Street Chinese Benevolent Association in San Anselmo, California. Trainer Kirk Turner of East Bay used clicker training with Shing Ling-hua, and after her death continued work with two other Poodles from the same breeder. Developing a methodology for the training has been a goal of this program, which has been subjected to the important peer review process that gets a study more serious attention from the scientific community.

Further Studies

A study in California has been testing dogs’ ability to detect lung cancer, while one in England is working with prostate cancer.

Dr. Donald Broom of England’s Cambridge University Medical School and fellow researcher Barbara Somerville have been working on a study of 16 pet dogs who detected cancer. Each of the dogs showed signs of being anxious and upset, appearing to consider the cancer a threat to the owner.

One dog found a tiny breast cancer on the owner, it was removed, and the dog lost interest. That was reassuring to the owner. Three months later the dog started becoming agitated again when sitting on her lap. Wisely, the owner returned to the hospital, where a tiny piece of previously-missed cancer was found.

This study is important for researching the types of situations that may actually occur more often for most of us than having a trained cancer-sniffing dog check us. The medical, the research and the dog training experts continue to debate how to set up programs for cancer detection dogs to be widely used.

Meanwhile, your dog is already in your home and may well be the world’s leading expert on your personal scent. Whenever a dog behaves oddly, it pays to consider whether the dog is alerting on something you need to know. Lives have been saved in many ways, including disease detection, by the loving family members we call dogs.