North Carolina Wildlife Resources Commission

Whirling Disease

On July 27, 2015, whirling disease was confirmed in rainbow trout collected from Watauga River in Watauga County– the first occurrence of the disease in North Carolina. Whirling disease affects fish in the trout and salmon family with rainbow and brook trout, two species found in North Carolina waters, being the most susceptible. The disease, caused by the microscopic parasite Myxobolus cerebralis, damages cartilage and skeletal tissue in trout, causing them to swim in a whirling motion. 
 
While often fatal to juvenile trout, the disease does not infect humans or pets, and eating an infected fish is not known to cause any harmful effects. 
 
Over the next few weeks, Wildlife Commission staff will be collecting trout from Commission-owned hatcheries, as well as from the Watauga River and tributary streams. Staff will send the collected fish to the Fish Disease Laboratory at Auburn University for testing. Staff is working closely with N.C. Department of Agriculture and Consumer Services to sample commercial aquaculture operations in the area where the infected trout were found.
 
Bookmark this page and check back frequently as we will update this page as test results and more information about whirling disease in North Carolina becomes available.

How Can You Help

Do not transport live fish from one water body to another.

Even if a fish looks fine on the outside, it may carry the whirling disease parasite or other pathogens, and can introduce disease. Illegal stockings can result in unwanted introductions that can have irreversible consequences. The Commission requires a stocking permit to stock any fish into North Carolina’s public waters.

Clean carefully all equipment such as boats, trailers, waders, boots, float tubes, and fins.

Rinse all mud and debris from equipment and wading gear, and drain water from boats before leaving the area where you’ve been fishing. The spores of the whirling disease parasite are known to adhere to these kinds of materials and can potentially be carried on gear from one stream to another. Careful cleaning using disinfectants such as household bleach will kill all forms of the parasite and reduce the risk of spreading this and other aquatic nuisance species. Remember to rinse your equipment thoroughly after using bleach to prevent this chemical from entering bodies of water.

Dispose of fish parts carefully when cleaning fish.

Dry disposal is best; dispose of the carcass in the garbage, by deep burying, or by total burning. Please do not dispose of fish heads, skeletons or entrails in any body of water. This can spread parasites and disease. Also, don’t discard entrails or heads of fish down a garbage disposal. The whirling disease parasite can survive most water treatment plants and infect areas downstream.

Contact the Commission if you observe signs of whirling disease in fish.