West Nile virus claims another horse as cities map responses

SEDALIA, Mo. -- West Nile virus has killed a second horse in Pettis County, one of at least 10 counties around the state where the mosquito-borne virus has been detected.

So far, samples from 13 horses from around Missouri have tested positive for West Nile at the University of Missouri's Veterinary Medical Diagnostic Laboratory in Columbia, assistant lab director Gayle Johnson said.

That number includes the miniature horse found dead Friday in Sedalia and another Pettis County horse that was euthanized July 28.

All 13 horses died of encephalitis, a swelling of the brain that can result from West Nile virus, Johnson said.

Chances that a horse bitten by an infected mosquito will develop encephalitis are probably less than 1 percent, Johnson said. A vaccine for West Nile is available for horses, but Johnson recommended that owners talk to their veterinarians about administering it.

Fair set to start

The latest Pettis County case was confirmed Wednesday -- the eve of the Missouri State Fair, which was expected to draw about 2,000 horses to Sedalia during its 11-day run, fair director Mel Willard said.

Officials with the state's Division of Animal Health are checking for signs of West Nile as well as other diseases in horses at the fair.

"We've really had a very high level of awareness," Willard said.

Horses are visually inspected as they arrive at the fair, and veterinarians routinely check the horses in the barns also, said Dr. Taylor Woods, state veterinarian. A lack of coordination in an animal including staggering, a drooped head, and ears flopped forward could be an indicator of West Nile.

Fair organizers also have taken precautions against mosquitoes. Standing water on the fairgrounds has been eliminated to discourage mosquito breeding, and parts of the fairgrounds have been sprayed with insecticide, Willard said.

Barbara and Paul McDannald, from Sarcoxie, said they have 10 horses at the fair.

"I think they have done an excellent job of preparation and controlling the flying insects here," Barbara McDannald said. "All the media hype raises concerns, but if we were worried we would not be here."

Burke Anderson, of Kansas City, a steward at the fair, said officials have been vigilant about spraying for bugs and taking away the habitat where mosquitoes can breathe.

"I haven't seen a mosquito or a fly or a bug on the fairgrounds, and I've been looking hard," he said.

West Nile was first detected in Missouri last September with the discovery of stricken birds in the St. Louis area. This year, the virus has marched steadily across the state. Infected birds have been found in 10 more counties, though no human cases have been reported.

Checking the traps

More communities are looking for -- and sometimes finding -- virus-carrying mosquitoes in traps.

In Branson, animal control officer Jeff McRoy has added mosquito patrol to his duties. Under a 12-week contract with the State Health Department, McRoy is collecting mosquitoes in five traps for testing at the department's lab in Columbia. The city also has sent four dead birds for testing. None has been found to carry the virus, said Branson Health Department Director Linn Smith.

Some cities, such as Independence, spray regularly for mosquitoes in spring and summer.