Disease-Detecting Dogs: Canine Smell – the Most Powerful Diagnostic Tool for Parkinson's Disease

A dog's sense of smell is one of their most highly developed cognitive tools. It allows them not only to locate food and identify other animals but also—as recent research shows—to detect subtle changes in human odor associated with serious medical conditions. Parkinson's disease may be one of them.

Dogs are considered the ultimate example of domestication for good reason. Their sense of smell is a true biological phenomenon—hundreds of millions of olfactory receptors allow them to detect scents that humans cannot even register.

More and more research indicates that dogs are capable of detecting odors associated with disease processes occurring in the human body – including those that remain invisible to modern medicine.

According to a study published in the Journal of Parkinson's Disease , dogs can detect Parkinson's disease by the scent of sebum, a substance secreted by the skin. One of the early symptoms of the disease is seborrheic dermatitis , which changes the composition and odor of skin secretions.

The study involved several dozen dogs who underwent training based on odor samples collected from sick and healthy individuals. They were rewarded with treats for correctly identifying a "positive" sample and ignoring a "negative" one.

The results of the experiment were promising:

• Sensitivity (i.e. accurate identification of sick people) reached 80% .

• Specificity (i.e. correct indication of healthy people) – as much as 98 percent .

This significantly exceeds the effectiveness of previous studies, for example in bladder cancer, where dogs achieved an effectiveness of only 40%.

Moreover, dogs were able to recognize Parkinson's even in patients suffering from other diseases, which may indicate the exceptional precision of their sense of smell.

Claire Guest, one of the study authors, emphasizes:

Early diagnosis offers a chance to slow the progression of the disease and alleviate its symptoms. While dogs won't replace medical technology, they can be a valuable aid in developing effective diagnostic tests.