Frieda the K9MD medical detection dog.
Cancers detected at an early stage are more likely to be treated successfully and starting the treatment while the cancer is small and confined greatly improves the survival rate. There is, however, a lack of diagnostic tools for early detection of some cancers, while other diagnostic tools are invasive or have poor accuracy and therefore not readily used by the general public or are not recommended routinely as screening tests.
An alternative to currently used molecular and physical cancer screening techniques, is the use of medical detection dogs to identify volatile organic compounds (VOC) released from tumours. While it is still unclear what exact markers dogs identify, it has now been established that changes in the cell’s metabolism due to a variety of diseases leads to the release of VOC that are distinct from VOC released by healthy cells.
A dog’s sense of smell can detect stable concentration thresholds of 1–2 parts per trillion, which is comparable to detecting a teaspoon of sugar in two Olympic sized swimming pools of water.
Apart from having more scent receptors in their nose (300 million compared to 5 million in humans), dogs use a larger proportion of their brain to analyse scent, and can therefore distinguish many more compounds.
Dogs are routinely trained and used to detect explosives, food, drugs, track missing persons, and track medical conditions – such as changes in blood sugar levels in diabetics.
In recent years, medical detection dogs have been trained internationally to identify cancer in patient samples, successfully detecting prostate, lung, bladder, skin, breast, and ovarian cancers.
The K9 Medical Detection New Zealand Charitable Trust (K9MD) are collaborating with a team of clinicians and researchers from the University of Otago, lead by Professor Sarah Young, to establish detection of cancers, infectious diseases and metabolic disorders by medical detection dogs in New Zealand.
The German shepherds Frieda and pup Levi are currently in the early training stages as medical detection dogs.