Allegheny National Fish Hatchery
Northeast Region

Fish Health

The goal of the hatchery is to produce healthy, disease free fish for restoration purposes. Healthy fish are produced in good quality water, fed a high quality diet, and are cared for to reduce stress and the introduction of fish pathogens.

Pathogens can refer to viruses, bacteria, parasites, or anything that can cause the fish to ‘catch’ a disease.

In order to determine the basic health of our fish, we monitor them daily, watching for exterior signs of disease (cysts, fungal growth etc.); we also perform necropsies (dissections) on mortalities as they appear. Tissue samples from these mortalities are sent to the Regional Fish Health Center for more detailed analysis.

In order to maintain our disease classification the facility must undergo a thorough annual inspection by Fish Health Biologists.
For more information on this process please click here (

The IPNv that depopulated Allegheny in 2005 was first detected through incidental mortality (a dead fish that was necropsied and sent to the Fish Health Center), and it was confirmed in multiple groups of fish by a station wide fish health inspection. This was beneficial as there were no exterior signs of the disease, and such an inspection prevented the unintentional release of the virus into the lakes. Allegheny fish were considered ‘carriers’, as we had not experienced and outbreak of mortality related to this virus.



Viral Hemorrhagic Septicemia is a disease of fish which is not native to North America. Accidentally introduced to this country, it has had significant impacts on fish populations in the Northwest, and more recently a new strain has been detected in various species through out the Great Lakes watershed. This has led to significant interstate transfer limitations put in place by the US Department of Agriculture (USDA) Animal Plant Health Inspection Service. A full review of their policy can be found at: (key word VHS)

Allegheny NFH has not tested positive for this disease. When fish are returned to the facility, we will continue to adhere to strict biosecurity practices, as well as regular fish health inspections to ensure that this virus does not affect the facility.

Last updated: December 15, 2011
All images by FWS unless otherwise noted
Allegheny National Fish Hatchery
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