A horse in Aiken County, South Carolina, has tested positive for West Nile virus (WNV), the Equine Disease Communication Center (EDCC) reported Nov. 4. This is the first case in Aiken County and the fourth case of WNV in South Carolina horses confirmed this year.
“The case was a 6-year-old Thoroughbred gelding that had been vaccinated approximately 10 months ago,” the EDCC said. “The horse is currently quarantined and recovering.”
In 2017, officials confirmed 10 cases of WNV in South Carolina horses, according to USDA Animal and Plant Health Inspection Service data.
West Nile virus is transmitted to horses via bites from infected mosquitoes. Not all infected horses show clinical signs, but those that do can exhibit:
Studies have shown that vaccines can be effective WNV prevention tools. Horses vaccinated in past years need an annual booster shot, but veterinarians might recommend two boosters annually—one in the spring and another in the fall—in areas with prolonged mosquito seasons. In contrast, previously unvaccinated horses require a two-shot vaccination series in a three- to six-week period. It takes several weeks for horses to develop protection against the disease following complete vaccination or booster administration. In addition to vaccinations, owners should work to reduce mosquito population and breeding areas and limit horses’ mosquito exposure by: