Published August 27, 2010, 12:00 AM

Viral disease kills thousands of birds on Minnesota lakes

Pelicans, cormorants and gulls are dying on several Minnesota lakes this summer, apparently from a viral disease that flares up every two years.

By: John Myers, Duluth News Tribune

Pelicans, cormorants and gulls are dying on several Minnesota lakes this summer, apparently from a viral disease that flares up every two years.

The Minnesota Department of Natural Resources reported Thursday that birds have died from Newcastle disease on Vermilion, Leech, Lake of the Woods, Wells and Marsh lakes. More than 1,000 gulls, 1,000 pelicans and 500 cormorants have perished.

“We were doing a pretty massive cleanup effort on Marsh and Vermilion,’’ said Erika Butler, DNR wildlife veterinarian.

The dead birds are burned using charcoal to avoid passing on the disease. It’s hoped the disease will run its course before large flocks form to migrate south. It spreads in feces and carcasses.

Tests have confirmed that cormorants on Marsh and Wells lakes died from Newcastle disease. It’s not yet certain what cormorants died from on Vermilion and Leech, with tests results expected within two weeks, Butler said.

“It’s the same pattern we saw on March Lake, so we suspect Newcastle there as well,’’ Butler said.

Likewise, the cause of death for pelicans and gulls on Lake of the Woods hasn’t been determined. Other possible diseases include West Nile disease and botulism.

So far, no birds have tested positive for avian influenza, Butler said. The specific strain of Newcastle disease was confirmed this week by the National Wildlife Health Center in Madison.

The current Newcastle outbreak is similar to one in 2008 that killed about 2,400 water birds in Minnesota, but is still far less severe than a 1992 outbreak of Newcastle that killed more than 35,000 birds across several Midwestern states.

A viral avian disease that existed first in domestic birds, Newcastle was first confirmed in wild birds about 1990. The virus, which attacks the nervous system and other organs, causes birds to suffer several symptoms, including gasping and coughing, loss of appetite, muscular tremors, drooping wings, twisting of head and neck, circling, paralysis, swelling of the tissues around the eyes and neck, reduced egg production and misshapen, rough- or thin-shelled eggs.

Newcastle rarely affects humans. When it does, it generally causes a relatively mild pink eye.

Newcastle disease has not been detected in Minnesota’s domestic poultry flocks this year. If birds show clinical signs suggestive of this disease, producers should immediately contact their veterinarian or the Board of Animal Health at (320) 231-5170. People who see wild birds they suspect are infected should call their nearest DNR wildlife office.

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