PARENT SESSION
PS1 - Wildlife Toxicology
Sunday, 17 November 2002
8:00 AM to 6:30 PM
Exhibit Hall
(P026) Investigating the cause of AVM in bald eagles and waterfowl.
Birrenkott, Anna*,1, Hains, John2, Wilde, Susan3, Fischer, John4, Murphy, Thomas5, Bowerman, William1, 1 Clemson University, Pendleton, SC2 US Army Corps of Engineers, Calhoun Falls, SC, USA3 University of South Carolina-Baruch Institute, Charleston, SC, USA4 University of Georgia, Athens, GA, USA5 South Carolina Department of Natural Resources, Green Pond, SC, USA
ABSTRACT- Avian Vacuolar Myelinopathy (AVM), a disease causing microscopic lesions in the white matter of the central nervous system, has killed over 90 bald eagles (Haliaeetus leucocephalus)and an unknown number of waterfowl, particularly American coots (Fulica americana), in the southeastern United States. The cause of AVM is unknown despite extensive research. We investigated the possibility that aquatic weeds, including Hydrilla verticillata, may be directly or indirectly responsible for the disease. A trial in which bobwhite quail (Colinus virginianus) and mallard ducks (Anas platyrhynchos) were exposed to Hydrilla verticillata collected from Lake Strom Thurmond (on the SC-GA border) during an AVM outbreak revealed no AVM-characteristic vacuolization in the quail and inconclusive evidence for diagnosis in the mallards. Two types of cyanobacteria that potentially produce neurotoxins, Pseudanabaena catenata and Hapalosiphon fontinalis, were observed in prominent colonies on the hydrilla. When exposed to Pseudanabaena catenata by oral gavage, mallards were AVM-negative. Ongoing trials include dosing mallards with a combination of P. catenata and H. fontinalis and dosing exclusively with H. fontinalis.
Key words: avm, eagles, cyanobacteria, toxins