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Clicking for Cancer

The olfactory power of dogs has made headlines again this month, with new research supporting our canine friends' ability to "sniff out" the presence of cancer. While these findings continue to astonish many, one aspect won't surprise fans of operant conditioning: the dogs in this study were clicker trained.

Dog nose

In the latest study, to be published in the March 2006 issue of Integrative Cancer Therapies, researchers in California presented five professionally clicker trained dogs with breath samples from 83 individuals with cancer (55 with lung cancer and 31 with breast cancer), and a healthy control group of the same number. The five dogs, ranging from 7 to 18 months old, included three Labrador retrievers (two males and one female) and two Portuguese water dogs (one male and one female).

During the course of the four-month study—involving over 12,000 videotaped scent trials—the dogs performed exceptionally well. The dogs' ability to correctly detect lung and breast cancer, at both early and late stages, was approximately 90%. This high rate of accuracy was present even when adjusted for smokers. These results suggest that breath analysis may one day serve to significantly reduce the current uncertainties in cancer diagnosis.

Rather than employing packs of canine lab assistants, scientists envision the creation of an "electronic nose," programmed to detect whatever compounds these dogs are detecting. Research and development in this area are pending. As the researchers explain, "Our study provides compelling evidence that cancers hidden deep within the body can be detected simply by examining the odors of a person's breath. The fact that it was dogs who did this does not detract from the novelty of our findings. The dog's brain and nose is currently one of the most sophisticated odor detection devices on the planet...technology now has to rise to meet that challenge and it remains to be seen whether chemical analysis can meet the level of the dogs."

"These results suggest that breath analysis may one day serve to significantly reduce the current uncertainties in cancer diagnosis."

While the latest news of canine super-sniffers offers more hope for a clinical application, this possibility was first noted in 1989. In an article published in the journal Lancet, doctors reported that a female patient had sought medical attention after her dog (a Border collie/Doberman cross) became highly interested in a mole on the patient's leg. The dog would sniff exclusively at the mole—ignoring the patient's other moles, even when clothed—and ultimately attempted to bite the mole off. The mole turned out to be cancerous. By alerting its owner, the dog may have saved her life. This unusual experience led the article's authors to hypothesize about the olfactory capacity of dogs.

More recently, in September 2004, an article in the British Medical Journal revealed that researchers in England had successfully trained dogs to detect bladder cancer in humans using urine samples. This stunning accomplishment was also accomplished with clicker training. (Read Karen Pryor's article on this study: Cancer Dogs Sniff the Diagnosis.)

Today's researchers—and dogs—working on cancer detection are building on the work of pioneers before them, and have opened the door to myriad other research exploring the ways in which canines might become expert cancer diagnosticians. Clicker training is sure to appear as the subplot to future headlines, as trainers—both professional and amateur—turn to the benefits and results that only clicker training can provide. Inspired? Try scent discrimination with your own dog. Steve White, a ClickerExpo faculty member who teaches courses on scent discrimination, is an expert in this field (www.i2ik9.com). Here is a brief intro, written by Karen Pryor, on Steve's method of applying scent discrimination to tracking:

K9 Police Officer Steve White has developed what I think is a wonderful clicker way to start training tracking. He calls it Scent in a Bottle. He presented it at one of my seminars in Seattle years ago. I'm sure he's taken it a lot further by now, but since I moved to Boston I am somewhat out of touch with West Coast events. I don't want to steal his thunder, but here's my take on it as Steve taught it to me then.

Get a spray bottle of some kind—Steve used a backpack-type garden sprayer that you pump up, so you can carry a lot of water. Soak a sweaty T-shirt in a bucket of water overnight, to get a good human scent. Load the sprayer with this water. Go to a parking lot and lay a straight line of this scented water about four yards long on the pavement. The point is, YOU can SEE it, so you can tell when the dog is working on the scent. Click the dog for noticing the line, then for sniffing at it, then for nosing along it.

When Steve did this at one of my seminars, we had about twenty dogs participating, on a dozen different lines. People clicked for audible sniffing, and for coming back to the line if the dog veered away, and so on. Many dogs just started following the track right away; I have two funny photos somewhere of a Pharaoh Hound following the line, and then, having been clicked, whipping its head around toward its owner with an expression of astonishment on its handsome face—"You mean I get clicked for THAT?"

Once the dog has the idea, you can lay longer lines and make corners (I would teach cornering this way, and early, with the clicker). Then carry the track across short distances where you can NOT see it, i.e., across patches of grass, so you learn to trust the dog. Then I'd try making the track a bit gappy, so the dog has to cast around to find the next part. If you need behavior related to articles, I'd teach that on a visible line, too. I think I'd also teach the dog that the game is tracking, and not doing anything else—by putting people, tennis balls, hotdogs, and other enticements outside the track and clicking and jackpotting the dog for going right past such temptations, all on the visible track. (You may have to re-spray from time to time, especially on hot days.)

You can do all this by yourself, with no one telling you you're wrong and your method is crazy. The benefit is not that the dog learns to track; he knows that. It's that you learn to trust him on the track, and you learn to read his behavior when he is not on the track, on the track but confused, off the track but searching for it. And he learns the other things you want, such as whether he has to keep his head down all the time, what to do at corners, how to respond to articles, etc. There are different requirements for different tracking sports.

When you go to tracking human footprints in an open field, you can also help yourself (the dog doesn't need help) with flags, or some other tip to you, so you can check on and thus trust the dog. Move these additional cues around and fade them after one or two tries, so the dog doesn't start to use them. Good luck!

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