LEWISTON, Idaho (AP) -- A deadly disease has forced federal fish managers at the Dworshak National Fish Hatchery to kill tens of thousands of juvenile steelhead.

Hatchery Manager Larry Peltz says two holding ponds at the facilty were infected with a disease called Infectious Haematopoietic Necrosis -- or IHN.

Peltz told the Lewiston Tribune the fish were killed to reduce the threat of the viral disease spreading to other holding ponds.

The kill is the second in recent weeks of juvenile fish at hatcheries that help bolster Idaho's fish populations.

Last month, about 40,000 sockeye salmon were killed at an Oregon hatchery that is raising fish destined for Idaho streams.

INH infects salmon and trout and can be fatal, while survivors an outbreak can carry the virus and pass it on.

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Information from: Lewiston Tribune, http://www.lmtribune.com

Copyright 2010 The AP.