The Burrill Report


My dog’s nose is a bit of a wonder. It’s just cold and wet enough that he can prod me with surprising effect when he wants to eat or go outside. It also has a way of winding up in places it doesn’t belong when we go to the dog park. But it turns out there actually might be some medical value in his snout.

A study published online in the journal Gut found that a specially trained Labrador retriever was able to reliably sniff out colorectal cancer from patient breath and stool samples. In fact, the dog was able to do so with 95 percent accuracy for the breath test and 98 percent accuracy for the stool test, compared with conventional colonoscopy. Colonoscopy is a procedure that involves placing a tube with a camera at its end where even man’s best friend wouldn’t want to go.

Though the researchers from Kyushu University and Fukuoka Dental College are quick to point out training dogs to sniff out cancer would not be practical because of the cost and time needed to train them, they say the findings suggest chemical compounds for specific cancers circulate throughout the body and could provide the basis for new diagnostics. For instance, the fecal occult blood test, which detects blood in stool samples is an effective and non-invasive method for diagnosing bowel cancer, but it is only able to pick up early stage disease in one in 10 cases.

Zeroing in on the volatile organic compounds that produce the odors detected by the dog could provide new and needed means of early detection.

In the study an 8-year-old black female lab trained by the St. Sugar Cancer Sniffing Dog Training Center in Chiba, Japan tested 48 samples from patients with colorectal cancer and 203 samples from volunteers with no history of cancer and 55 samples from patients with a previous history of cancer. A single cancer sample was place randomly in one of five sample stations for the dog and four control samples were placed at the other stations.

The dog successfully identified which samples were cancerous, and which were not, in 33 out of 36 breath tests and in 37 out of 38 stool tests, with the highest detection rates among those samples taken from people with early stage disease.

The findings are in line with earlier studies that found dogs were able to sniff out melanoma, bladder, lung, breast, and ovarian cancer. What the new study found was that the dog had greater accuracy at detecting early-stage cancer. The study also found that smoking, benign colorectal disease, inflammatory disease or the presence of human hemoglobin or transferrin didn’t affect the dog’s ability to detect the disease.

All of this, though, may mean I may owe my dog an apology. All this time when I thought he was being rude at the park by sticking his nose in other dogs’ business, as it were, may have been done in the name of advancing medicine. What a good boy.






February 03, 2011
http://www.burrillreport.com/article-what_a_dog%e2%80%99s_nose_knows.html