THROUGH THE NOSE OF A SNIFFER DOGSally-Jay StrongHow dogs are being used to sniff out disease?
Certain types of cancers cause specific changes in the scent of our bodily secretions to such a degree that a highly sensitive and trained nose can not only detect cancer, but even specific variants of the disease. Detectable in the skin, breath, saliva, sweat, urine and faeces, canines can be trained to sniff out anything from melanoma to prostate and lung cancer. Some of these are consistently detected in the very early stages.
Even untrained dogs have persistently drawn their owners’ attention to a troublesome area, only to discover after a visit to the doctor that the pup had found a real problem. Using their 22 million scent receptors, it’s easy for a dog to smell if “something isn’t right” and the process by which they detect disease is completely non-invasive. With an 88% success rate for detecting breast cancer and 99% for lung cancer (not to mention all the other types) as well as 98% success rate using blood samples for detection, I’d say the science very much proves it.

Dina Zaphiris, founder of non-profit cancer-dog training organisation “In Situ Foundation”, developed the first protocol for training cancer-detecting dogs. It takes about 300 samples sniffed before a canine can accurately and consistently distinguish a cancer cell from a healthy one, although once they have done this, they are generally able to pick out unhealthy samples from most new stimuli.

Dogs aren’t just pro’s at helping cancer patients, they are now being used to detect and help people with Epilepsy, Narcolepsy, Parkinsons, Diabetes and can even detect a Migraine up to 2 hours before it happens (with a 54% accuracy.) In a pilot study at the University of Helsinki, dogs were taught to recognise the odour signature of the COVID-19 virus present in urine samples. The animals were able to accurately distinguish the disease almost as reliably as a standard PCR test. Further double-blind studies are being conducted in Finland, as are similar studies in the UK. 
Realising that “cancer sniffing” is such a specialised profession and trained animals are always likely to be in short supply, Andreas Mershin, a research scientist at the MIT Center for Bits and Atoms, set about conceiving of a solution.
In the latest twist on this innovative approach he performed a study using research obtained from dogs’ diagnoses of patients with prostate cancer to inform a machine learning algorithm in order to effectively teach artificial intelligence to sniff out cancer too! Although it is just a proof of concept study and all of the subjects participating were “Gleason 9” (significant amounts of cancer in the region) early results are extremely encouraging.
As far as “dogs with jobs” go, these critters deserve a round of apaws!