Levi loves what he does. He gets picked up each morning at 8:30am, happy and excited to go to work. He spends his time investigating samples, figuring out whether they contain cancer or not. His payment – toys and play time.
Levi is a German Shephard with a finely tuned olfactory system - a nose perfectly adapted to smelling, around 225 million scent receptors and a large part of the brain designated to distinguishing smells.
He is part of the K9 Medical Detection Charitable Trust team based at AgResearch in Invermay. Alongside his colleagues Wētā, Frieda, Magic and puppy Ace, Levi has been training to do one job extremely well – sniff out bowel cancer.
Trainer Courtney Moore works with the dogs – helping them to ‘imprint’ on the cancer scent from an early stage. It is unclear exactly what the dogs are sniffing out - it is likely to be metabolites or volatile organic compounds released by the cancer cells into the solutions they are in - but the dogs are able to distinguish a unique cancer 'scent'. The imprinting is part of the first ‘proof of concept’ phase, a validation step that the dogs must pass through where they show they can selectively pick which of the saline samples contain the cancer cells, and ignore those that contain healthy cells.
Levi has already passed this validation step with flying colours with regards detecting bowel cancer, and the team hope that Wētā will soon follow. Frieda has recently passed for prostate cancer detection with 100% selectively and specificity. The next phase is a test of diagnostic accuracy, says director Pauline Blomfield. This would involve the dogs investigating urine samples from patients.
The goal is to provide a non-invasive, value-added tool to existing cancer screening methods. In addition, identifying the volatile organic compounds the dogs are detecting could provide a further opportunity to develop specific and selective diagnostic tests based on these molecules, says Professor Sarah Young of the University of Sydney, one of the scientists who work with K9 Medical Detection.
While it is still relatively early days in terms of the dogs providing help with cancer diagnoses, the dogs have achieved good results so far and the team have faith in their strong work ethic and amazing noses. Levi is just happy to do something he loves each day.
- The papers mentioned in this episode are this 2021 article in PLOS One attempting to identify the volatile organic compounds the dogs are smelling and this 2015 article in the Journal of Urology reporting on the Italian based prostate cancer trial using patient urine samples, this trial was mentioned Dr. Guest in this RNZ interview in 2015.
- As mentioned by Professor Sarah Young, groups are also currently investigating the use of trained detection dogs to identify SARS-CoV-2 infected samples. This was also discussed on Nine to Noon, listen here.
- You might also be interested in previous Our Changing World episodes such as one about Detector Gadget the conservation dog, Dogs that can sniff out pest fish, and Clever Canines - about how smart dogs are.