Mysterious brain disease kills eagles, ducks and coots in Eastern USA

Abstract

The US Department of Agriculture recently issued a Wildlife Health Alert regarding avian vacuolar myelinopathy (AVM), which afflicts wild waterfowl and bald eagles Haliaeetus leucocephalus. AVM was first documented in bald eagles and American coots Fulica americana in 1994, and has subsequently been reported from several duck species and Canada geese Branta canadensis (http://www.aphis.usda.gov/vs/ceah/cei/notices.htm). AVM produces lesions in the white matter of the brain and in the spinal cord, causing difficulty flying, walking and swimming. The disease appears to be confined to the immediate vicinity of lakes, which are the sites of exposure. The disease is believed to be caused by a naturally occurring or manmade neurotoxin, with exposures and documented mortality thus far associated primarily with manmade reservoirs (http://inet.mvk.usace.army.mil/offices/od/odm/avm/). AVM has not been seen in domestic waterfowl, and there are no data concerning infection in humans. Bald eagles apparently contract the disease after preying on infected coots.Although none of the birds afflicted with AVM is suffering major population declines, it is worrisome that a species that was once endangered, such as bald eagles, might now face an emerging disease as a new threat. AVM might well be a harbinger of things to come, with emerging new diseases representing one of the greatest risks facing wildlife and species of conservation concern (http://www.nwhc.usgs.gov/). PK