What Does It Look Like?
At a low level of infection, fish might not display any symptoms. As the infection becomes greater, however, fish will display widespread hemorrhages (bleeding) throughout body surface (eye, skin and fins) and within the internal organs (swim bladder, intestine, kidney etc). Because of the bleeding, gills and liver might appear pale. Sick fish will often be listless, swim in circles, and are frequently observed at the surface of the water.
NOTE: Confirming VHS infection requires sophisticated laboratory testing. A diagnosis cannot be made based solely on observation because many different diseases of fish have very similar symptoms.
For more information, download the VHS flyer.
Species Affected
To date, VHS has caused large-scale mortality in
- black crappie in Budd Lake (Michigan)
- bluegill in Budd Lake (Michigan)
- common carp in Lake Ontario
- freshwater drum in Lake Ontario, Lake Erie and Lake Winnebago (New York)
- gizzard shad in Lake St. Clair, St. Clair River and Lake Erie
- Great Lakes muskellunge in Lake St. Clair
- round gobyin Lake Ontario
- white bass in Lake Erie
- yellow perch in Lake Erie and Lake St. Clair