West Nile Virus kills E.Texas horse, others being tested

By LYNN MONTGOMERY | East Texas Edition

October 3, 2002 -- The West Nile Virus (WNV) has claimed a horse's life in Wood County.

The 23-year-old horse was euthanized on Sept. 22 by Dr. David Howton, veterinarian at Winnsboro Veterinary Medical Center.

"We began treating the horse on Tuesday, Sept. 17, and then put it down on Sunday, the 22nd," Howton said on Sept. 27.

WNV is a disease that is carried by an infected mosquito that has bitten an infected bird. The only birds that carry WNV are bluejays, crows, and hawks.

"Currently, we have eight positive bluejays in Cass County, one positive bluejay in Titus County, two positive bluejays and one positive crow in Nacogdoches County, one positive bluejay in Smith County and one positive bluejay in Gregg County as of Sept. 27," said Dr. James Wright, regional zoonosis veterinarian with the Texas Department of Health.

"As of Sept. 26, 443 horses in 83 counties had been affected by West Nile Virus," said Carla Everett, public information officer for Texas Animal Health Commission (TAHC) who maintains the database for WNV.

Horses are diagnosed by bloodwork which can either be sent to a lab in Ames, Iowa or Texas Veterinary Medical Diagnostic Lab (TVMDL) in College Station.

As of Sept. 27, TAHC had not received confirmation of the confirmed West Nile case in Wood County, but Dr. M.G. Fearneyhough with TVMDL did confirm the animal had West Nile.

Public officials are still warning people to vaccinate their horses, not only for West Nile but also for Eastern encephalitis and Western encephalitis, diseases also transmitted by mosquitoes.

Dr. Bruce Lawhorn, a veterinarian and professor of veterinarary medicine at Texas A&M, said, "We are still stressing to vaccinate this year. Don't wait until March."

One type of mosquito that is in East Texas, according to the vet, can survive the cooler weather. Therefore, if the mosquito doesn't die, then it will be around to infect whatever it bites.

"Even though it is late in the season, because of that type of mosquito, we are stressing vaccinating," Lawhorn continued.

Vaccination is echoed by Howton. "We are going to have problems for the next 60 days. It doesn't frost until around Nov. 15 so mosquitoes are out there," Howton said. "Go ahead and vaccinate."

"People need to be reminded there have been confirmed cases of Eastern encephalitis in East Texas," Fearneyhough stated. "As of this week (Sept. 27), there are three confirmed cases in East Texas."

All the veterinarians Country World spoke with emphasized mosquito control, such as fly spray, even if horses have been vaccinated. Recommendations are to use a fly spray which contains "DEET."

Other ways to control mosquitoes are to eliminate standing water (emptying tires, buckets, troughs); use fly sheets at night or keep horses stabled during dawn and dusk; and use fluorescent lights in areas that need to be lighted.

There is no group of horses exempt from this disease, Lawhorn said. Cases have ranged in ages from 4 months to 36-years-old. Most cases tend to be in horses that are young, old, or have a compromised immune system.

Lawhorn added that one out of 100 horses (1 percent) bitten by infected mosquitoes will actually get the disease. Out of that 1 percent, only 25 to 30 percent actually die.

Howton said there was a colt in his Winnsboro clinic on Sept. 27 that was showing signs of WNV. Blood test results on the colt were not available.

Signs of WNV in horses are depression, elevated temperature, will not have good use of its limbs, poor appetite, will not feel well. These symptoms are also signs of rabies, EPM, equine encephalitis, and other neurologic diseases. If a horse shows any of these symptoms, contact your veterinarian immediately.