Dogs detect Parkinson's by smell, years before symptoms start: Study

(NewsNation) — Dogs can be trained to reliably sniff out Parkinson's disease from a person's skin secretions years before symptoms appear, a new study found.

A pair of dogs were trained to detect Parkinson's disease by smelling sebum — or oily discharge — from skin swabs of people with and without the neurological disorder.

When faced with 100 skin swabs as part of a double-blind trial, the dogs showed sensitivity of up to 80% and specificity of up to 98.3%, even if a person had other medical conditions.

Sensitivity is the ability to identify those with the disease, while specificity is identifying those who don't have the disease, according to the National Institute of Health. Essentially, that means there were few false negatives or false positives in the trial.

Parkinson's disease is a progressive movement disorder that causes brain neurons to weaken and eventually die. Symptoms include tremors and stiffness, which lead to difficulty walking, talking and completing daily tasks, per the NIH.

It has no definitive diagnostic test or cure, which means a dog's powerful nose could be pivotal with diagnosis and intervention. Researchers believe the disease can be found in sebum excretions before motor issues begin.

The trial, a collaboration by Medical Detection Dogs and the Universities of Bristol and Manchester, is the latest in a growing body of studies showing that dogs can help detect Parkinson's and other diseases by smell alone.

"Symptoms may start up to 20 years before they become visible and persistent, leading to a confirmed diagnosis," said Claire Guest, Medical Detection Dogs CEO and chief scientific officer.