Animals are driven by instinct. By default, they are extremely sensitive to changes in their immediate environment. Subtle physical and biological changes in their surroundings alert them way before a human being realizes danger. There is plenty of anecdotal evidence to suggest that animals are able to sense an impending storm or change in weather. When areas of low pressure move in, prey animals are reported to become highly excitable.
Of all the domesticated animals, dogs have mostly been employed to be of service to humans. Canines used by police and military to sniff bombs, landmines, and cadavers are legendary. Service dogs are trained to fulfill various requirements to improve the quality of our lives. Dogs guide blind people in their day-to-day activities and provide company to terminally ill patients. However, there are some animals that either inherently or by training are able to provide a health warning to humans. An example of this would be “Seizure Alert Dogs,” warning their owners of an epileptic attack, anywhere between 30 sec to 45 minutes before it actually occurs; thus helping the owner to avoid injury, and even death. It has also been reported that the presence of a dog actually reduced the seizure frequency.
By virtue of their superior sense of smell and trainability, dogs are ideal for differentiating smells. Bearing this uniqueness in mind, some dogs are being trained to sniff out cancer. The number of smell receptors in a dog’s nose is 10 times that of a human nose. When cells turn cancerous, the volatile organic chemicals released by these malformed cells are apparently distinctly different from those of normal cells. Previously, it was reported that researchers at the University of Pennsylvania initiated a study to use dogs for detecting early stage ovarian cancer. Recently, a team from the University of Arkansas for Medical Sciences has tapped the difference in odor between normal and cancerous cells to train Frankie, a German Shepard, to sniff thyroid cancer in urine samples of patients coming in for conventional diagnosis. Frankie’s diagnosis was accurate in 30 out of the 34 patients tested.
Although this experiment seemed successful, there are some arguments against using dogs for sniffing out diseases like cancer. Some scientists doubt the accuracy of such diagnosis and also the practicality of such an approach. Alternatively, researchers are trying to figure out the chemical composition of the odor that is sensed by these dogs. The ultimate aim is to use the information gained from a dog’s nose to develop an “electronic nose” that could be a diagnostic tool for cancers.
We might have to wait a few years for this diagnostic tool. Meanwhile, let us thank man’s best friend for yet another service.
"Dogs are not our whole life, but they make our lives whole."
—Roger Caras (photographer and writer)
Written by Mangala Sarkar Ph.D.