Dogs can detect Parkinson’s years before symptoms—with 98% accuracy

The study did not present the dogs with samples from "years before" and did not have an accuracy of 98%. It had a sensitivity (percent of positive samples called positive) of 70% for one dog and 80% for the other. Their specificity (percent of negative samples called negative) was 90% and 98%.

Since there were 60 positive samples and 40 negative samples, their accuracies were 82% and 91%, respectively.

Not 98%. And with samples from patients currently diagnosed (or controls).

What’s the false pawsitive rate?

And they won't tell you unless you train them.

I wonder if there have been studies on the benefits of pretreating Parkinson’s before you have a full blown condition. Otherwise, these dogs would give you the bad news and it’s just “enjoy dreading the day the disease finally hits ya”

Dogs can detect certain biomarkers in sebum (skin oils) that change with Parkinson's, but these headlines always exagerate the results.

No.