What Ever Happened to Whirling Disease?

April 24, 2025 By: Phil Monahan

Life Cycle of Myxobolus cerebralis, the parasite that causes whirling disease. via mtpr.org

Thirty years ago, the fly-fishing world was terrified by the discovery of whirling disease in Montana’s trout population. Would the rivers of Big Sky Country no longer live up to their legendary status? While the worst-case-scenario predictions never came true, some waters, such as the Madison, saw their rainbow populations reduce by as much as 95%.

Whirling disease is still present, but we don’t hear much about it. Why not? A fascinating interview on Montana Public Radio revisits the initial panic about whirling disease, as well as the decades-long recovery that’s still a bit of a mystery.

Click here for the full story at mtpr.org