Churchill Downs, Farms Take Steps Against West Nile Virus

Churchill Downs' primary weapon against the West Nile virus (WNV) sits in a clear, plastic vial on the desk of track superintendent Butch Lehr, according to AP writer Chris Duncan.

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, superintendent since 1981.

Eight horses in Kentucky have been diagnosed with WNV this summer and five have died. The mosquito-borne disease has also killed seven people this year, all in Louisiana.

The horse racing industry is trying to protect the animals from WNV, and there is a vaccine available for horses. The industry is still recovering from an illness that killed hundreds of foals and caused pregnant mares to abort last year.

While WNV doesn't appear to pose the same sort of threat as Mare Reproductive Loss Syndrome, Lehr and others aren't taking any chances. A 2-year-old colt died last fall at Churchill Downs from WNV.

"That was a learning experience for all of us," Lehr said.

The track already had a mosquito deterrent system -- angled, concrete ditches that drain water from horse barns. The ditches reduce standing water, where mosquitos breed.

Lehr wanted to do more. This spring, the track started using the vials of larvicide called Vectobac-G. The pellets were spread along the grassy perimeter of the track's infield and put in water-collecting basins. The track also set up sticky, yellow rolls of plastic sheets that trap mosquitos like flypaper.

The track hasn't had another case of WNV.

"It's never been a frantic situation, but we came to grips with this as a very real threat last fall," said John Asher, the track's vice president of communications. "There's nothing to prevent a single infected mosquito from flying across the fence. But we think we've taken every precaution we can."

Managers at some of Kentucky's lush horse farms are putting their trust in the vaccine, developed by Fort Dodge Animal Health and given conditional approval by the U.S. Department of Agricultre a year ago.

Frank Taylor, the manager of Taylor Made Farm in Nicholasville, said that since last summer every horse on the grounds is inoculated.

"Once we heard about the first few cases, we were proactive about it," Taylor said. "Now, it's part of the routine."

Every horse at Three Chimneys Farm in nearby Midway has also been vaccinated. Farm manager Dan Rosenberg said he's more worried about his employees becoming infected with WNV; there is no human vaccine.

Both farm managers say the foal deaths in 2001 still are a great concern.

"West Nile isn't significant. You may get one case, and there's about a 0.001 percent chance of that," Taylor said. "With the caterpillars, you might be talking about a third of your crop, and then, for a while, you still had no idea what was causing it. With West Nile, you know exactly what you're dealing with right off the bat and you know what you can do to prevent it."

Rusty Ford, who handles equine issues for the Kentucky Department of Agriculture, said the biggest mystery of WNV among horses is how indiscriminate it is.

The eight Kentucky cases this year occurred in six counties and were spread over at least 250 miles. The horses were of five breeds and their ages ranged from 1 to 13. Only two infected horses were Thoroughbreds, the primary breed in racing.

"It's quite widespread and there doesn't seem to be any common denominator," Ford said. "But I don't think you can classify that as a fear, because they're all isolated cases. It comes down to what horse gets bitten by what mosquito."

More on West Nile Virus at http://www.TheHorse.com/wnv

About the Author

The Blood-Horse Staff

The Blood-Horse is the leading weekly publication devoted to international Thoroughbred racing and breeding. Since 1916, the staff of The Blood-Horse has served the Thoroughbred community with the highest standards of journalistic excellence to provide comprehensive and timely editorial coverage and analysis.

Stay on top of the most recent Horse Health news with FREE weekly newsletters from TheHorse.com. Learn More

Free Newsletters

Sign up for the latest in:

From our partners