Newcastle Disease cause of water bird die-off in Big Stone County

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Newcastle Disease cause of water bird die-off in Big Stone County
(Released August 9, 2010)


Hundreds of double-crested cormorants and ring-billed gulls on Marsh Lake in Big Stone County have died from Newcastle Disease, according to the Minnesota Department of Natural Resources (DNR). As of Wednesday, about 500 cormorants and 400 ring-billed gulls had been found dead at the lake, which is near Appleton in western Minnesota.

More testing is being conducted to determine the strain of Newcastle Disease. Avian influenza tests, however, were negative.

Newcastle Disease is a viral disease that most commonly infects cormorants, but has also been documented in gulls and pelicans. Clinical signs of infection in wild birds are often neurologic and include droopy head or twisted neck, lack of coordination, inability to fly or dive and complete or partial paralysis. Juveniles are most commonly affected.

Newcastle can rarely affect humans, generally causing conjunctivitis, a relatively mild inflammation of the inner eyelids. It is spread to humans by close contact with sick birds. Wild birds can be a potential source of disease if they have contact with domestic poultry.

Area farmers need to practice sound biosecurity procedures, including monitoring their poultry flocks for signs of illness and taking steps to prevent wild birds from having contact with their domestic birds. If birds show sign of sickness, producers should contact their veterinarian or the Minnesota Board of Animal Health at 320-231-5170.

Another die-off of 50 of cormorants has been discovered on Wells Lake in Rice County. Samples are being tested, but the specific cause of the birds’ illness is unknown.

DNR and the U.S. Department of Agriculture’s Wildlife Services staff are conducting site clean-ups and collecting swab and carcass samples for lab analysis at both locations.

Newcastle Disease is not new to Minnesota. The last outbreak covered a seven-county area in 2008, when about 2,400 birds died. In 1992, multiple mortality events affected double-crested cormorant colonies across the Great Lakes, upper Midwest, and Canada, with more than 35,000 birds estimated dead.

Minnesota has about 39 nesting colonies of double-crested cormorants, 87 percent of which occur along with other colonially nesting water birds. Most active nesting sites have a long history of use, dating back to the 1960s and 1970s.