[ODFW-News] Hatchery euthanizes diseased fish

[ODFW News]

Oregon Department of Fish and Wildlife 	
Contact: 	Anne Pressentin Young (503) 947-6020	
Internet: www.dfw.state.or.us  Fax: (503) 947-6009
	
For Immediate Release	Thursday, October 9, 2003

Hatchery euthanizes diseased fish

SALEM - The Oregon Department of Fish and Wildlife euthanized 33,000 rainbow trout being held at Leaburg Hatchery Tuesday because they had an incurable disease.

The trout had been destined for release in the Salem area this fall. Replacement trout have been purchased from private trout grower Desert Springs Trout Hatchery by the U.S. Army Corps of Engineers to allow the stocking program to continue as scheduled. USACE funds Leaburg Hatchery.

The trout were diagnosed with the infectious hematopoietic necrosis (IHN) virus Aug. 29. Fish from this group had tested positive for the disease in spring 2003, but later recovered and tested negative. Leaburg Hatchery also was forced to euthanize trout last year due to IHN. 

IHN is a naturally occurring virus that initially attacks the blood-forming tissues of the kidney. External symptoms include lethargy, darkening of the skin and hemorrhaging at the base of the fins. Past experience shows that hatchery fish sometimes clear themselves of the disease. There is no known treatment.

Staff from the Eugene-area hatchery have worked with fish pathologists and other ODFW staff to minimize the chance of IHN infection in fish being raised for stocking in 2004. Hatchery staff will trap summer steelhead, the likely source of IHN, as they attempt to enter the hatchery will hold them below the hatchery water intake to prevent the virus from entering the hatchery. In addition, fingerling trout will be raised at other ODFW hatchery facilities until they are large enough to fight a potential infection, and additional steps are being taken to minimize cross contamination between ponds.

ODFW fish pathologists will continue to sample fish at Leaburg hatchery. If IHN infects more trout, additional steps will be taken to contain the disease. 

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Information and Education Division
Oregon Department of Fish and Wildlife
(503) 947-6002