What if dogs could “smell” Parkinson’s disease?

What if dogs could “smell” Parkinson’s disease?

It is known that dogs have sense of smell. Their sense of smell allows them, with training, to recognize people contaminated by many diseases, including cancer, malaria and Covid-19. A new study tells us more about the extraordinary abilities of canines when it comes to detecting human pathologies.

This research, published on the pre-publication site bioRxiv, focuses particularly on Parkinson’s disease, this neurodegenerative pathology which is characterized by the progressive disappearance of brain cells essential to the proper functioning of the entire body. Its authors, Lisa Holt and Samuel Johnston, claim that dogs can be trained to detect the specific odor that people with this disease have with an accuracy rate of more than 80%. And this, whatever their race.

A sense of smell 10,000 to 100,000 times more powerful than that of humans

Because doggies have a powerful sense of smell. It is estimated to be 10,000 to 100,000 more powerful than that of humans. Their sense of smell allows them to detect more odors than us and at much lower concentrations. However, recent scientific studies suggest that people with Parkinson’s disease have volatile organic compounds in their sebum that have a different odor than healthy people.

Lisa Holt and Samuel Johnston therefore wanted to see if dogs were able to “sense” Parkinson’s disease. To do this, they conducted an experiment involving 23 doggies of 16 different breeds, including Labrador retrievers, Hungarian Shorthaired Pointers, Mastiffs and Miniature Spitz dogs. The dogs had to sniff sebum samples, taken from 43 people with Parkinson’s disease and 31 volunteers without health problems.

An avenue for screening for Parkinson’s disease

To ensure the smooth running of the experiment, the selected dogs had previously completed training training lasting eight months. In particular, they learned to sit, bark, tap their paws or move their snouts when they identified an olfactory marker of Parkinson’s disease. During the experiment, the dogs received a reward, in the form of a toy or treat, each time they correctly identified a sebum sample.

On average, dogs were able to recognize people suffering from Parkinson’s disease 86% of the time. Furthermore, they did not react to “healthy” sebum samples in 89% of cases. “This study demonstrates that pet dogs can detect a target odor associated with Parkinson’s disease, which likely exists in the form of volatile organic compound(s).“, explain the researchers in their study.

While the findings of this study are promising, they should be taken with caution given the small number of dogs participating. But everything suggests that dogs could be valuable allies in the detection of Parkinson’s disease. Proof, if any more were needed, that dogs fully deserve the title of man’s best friend.