The U.S. Department of Agriculture and the Centers for Disease Control and Prevention yesterday confirmed that in Suffolk County, NY, at least one dead horse tested positive for the West Nile-like virus. Another 10 horses that displayed symptoms have confirmed West Nile-like antibodies. Additional tests on the tissue samples from the other dead horses, and on serum from the living horses, are pending.

This announcement brings the total of symptomatic horses to 22 in Suffolk County. Thirteen of the horses have died or been euthanized, while the other nine are recovering. Supportive therapy—given in the form of intravenous fluids and anti-inflammatory drugs—is all that can be done for the victims.

Veterinarians from the NY State Department of Agriculture and Markets and other practitioners assigned to federal agencies are conducting surveillance activities, including blood sampling of horses throughout Long Island and the Hudson Valley, as part of an emergency response effort coordinated by the USDA.

Meanwhile, officials with the USDA are developing a West Nile-like diagnostic test and conducting inoculation studies to determine the effects of the disease on U.S. livestock and poultry