Dogs Sniff Out Disease In Humans

July 11th, 2014

Early detection of prostate cancer has been enhanced through digital rectal screenings, but they are not always accurate, and may present the potential for discomfort. However, screening techniques are being tested that could change all of that, and they rely on the acute sense of smell of our canine friends.

In 2010, a study demonstrated that specially trained dogs were able to smell volatile organic compounds (VOCs) released into urine from the prostates of people with cancerous tumors. Since this study only involved 33 patients, the Italian research team set out to determine the dogs' detection accuracy in a larger sample. Italian researchers recently presented their findings at the 109th Annual Scientific Meeting of the American Urological Association in Orlando, Florida. They discovered that specially trained dogs were able to detect prostate cancer from urine samples with 98% accuracy. Dogs have approximately 200 million olfactory receptors in their noses, which is about 40 times what humans have. This heightened ability to trace scents has made them sought-after in the world of medicine.

The Italian scientists set out to see whether two highly trained dogs were able to detect prostate cancer-specific VOCs in the urine samples of 677 participants. Nearly half of the participants had prostate cancer and the testing environment was free from olfactory interference. They concluded that the dogs were able to detect prostate cancer-specific VOCs with a combined accuracy of 98%. Sensitivity to the compounds was 99% accurate, while specificity was 97% accurate.

The first dog’s overall accuracy for detecting VOCs was 99%, with sensitivity at 100% and 98% specificity. The second dog was able to detect VOCs with 97% accuracy, sensitivity with 99% accuracy and specificity at 96%.

Dr. Brian Stork, a urologist at West Shore Urology in Muskegon and Grand Haven, MI, who was not a part of the research, acknowledges that the results are a promising approach to cancer detection. He went on to say that the possibility of using dogs to identify cancer was something nearly impossible to imagine a decade or two ago, but now seemingly, it is reality.

The researchers also looked at how dogs are being used for detection of other cancers. It appears that trained detection dogs are also able to detect ovarian cancer in tissue and blood samples through sniffing out VOCs. Furthermore, a 2011 study conducted by researchers at the UK charity Medical Detection Dogs, found that these same compounds could also be indicative of bladder cancer, and so similar detection by these animals could be highly useful.

Medical News Today recently released a feature focused on how animals could help alert diabetic owners to high or low blood sugar levels based on being able to recognize a specific scent in their breath or sweat. Medical News Today also reported on a study revealing that dogs could provide new insight into Chiari malformation in humans, which is a condition that occurs when the lower parts of the brain are pushed down towards the spinal cord. Other research published in Genome Biology found that dogs could serve as a model for obsessive-compulsive disorder (OCD) in humans.

Detecting VOCs seems to be the first area that dogs are likely to be lending their skills for now. It is becoming more and more evident that it is not only dogs' intricate sense of smell that can aide the medical field, but they can also provide assistance in a plethora of other ways that are only beginning to be uncovered.