LOUISVILLE, Ky. — Churchill Downs' primary weapon against the West Nile virus sits in a clear, plastic vial on the desk of track superintendent Butch Lehr.
The vial holds birdseed-like pellets that release a chemical that kills mosquitoes in their larval stage. The chemical is otherwise safe and is harmless to horses, making it an ideal mosquito repellent for the home of horse racing's premier event, the Kentucky Derby.
"It does the trick," said Lehr, the superintendent since 1981.
The mosquito-borne disease has killed nine people in the United States this year, seven in Louisiana and two in Mississippi. Besides humans and birds, horses are the most vulnerable to the virus, and in Kentucky alone, eight have been diagnosed with West Nile this summer and five have died.
The horse racing industry is trying to protect the animals from West Nile, and there is a vaccine available for horses.