By: Joshua A Krisch
McBaine, a black and white springer spaniel, perks up and begins his hunt at the Penn Vet Working Dog Center. His nose skims 12 tiny arms that protrude from the edges of a table-size wheel, each holding samples of blood plasma, only one of which is spiked with a drop of cancerous tissue.
The dog makes one focused revolution around the wheel before confidently halting in front of sample No. 11. A trainer then tosses him his reward.
McBaine is one of four highly-trained cancer detection dogs at the centre, which trains purebreds to put their superior sense of smell to work in search of the early signs of ovarian cancer. Now, Penn Vet, part of the University of Pennsylvania’s School of Veterinary Medicine, is teaming with chemists and physicists to isolate cancer chemicals that only dogs can smell. They hope this will lead to the manufacture of nanotechnology sensors that are capable of detecting bits of cancerous tissue 1/100,000th the thickness of a sheet of paper.
Dr Cindy Otto, the founder and executive director of the Working Dog Center, conceived of a centre to train and study working dogs when, as a member of the Federal Emergency Management Agency’s Urban Search and Rescue Team, she was deployed to ground zero after the September 11 attacks.
“I remember walking past three firemen sitting on an I-beam, stone-faced, dejected,” she says. “But when a handler walked by with one of the rescue dogs, they lit up. There was hope.”
The Working Dog Center trains dogs for police work, search and rescue and bomb detection. Their newest canine curriculum focuses on sniffing out a different kind of threat: ovarian cancer. “Ovarian cancer is a silent killer,” Dr Otto said. “But if we can detect it early, that would save lives like nothing else.”
Dr Otto’s dogs are descended from illustrious lines of hunting hounds and police dogs, with noses and instincts that have been refined by generations of selective breeding. Labradors and German shepherds dominate the center, but the occasional golden retriever or springer spaniel — like McBaine — manages to make the cut.
What exactly are the dogs sensing? George Preti, a chemist at the Monell Chemical Senses Center in Philadelphia, has spent much of his career trying to isolate the volatile chemicals behind cancer’s unique odor. She is working to isolate unique chemical biomarkers responsible for ovarian cancer’s subtle smell using high-tech spectrometers and chromatographs. Once he identifies a promising compound, he tests whether the dogs respond to that chemical in the same way that they respond to actual ovarian cancer tissue.