Encephalitis has plagued the East Coast in 2000, with South Carolina the latest state under attack. South Carolina’s bout with at least nine cases of Eastern equine encephalitis (EEE) had horse owners on the defensive this fall.

“We have EEE cases every year, in horses and occasionally in emus or quail,” said Venaye P. Reece, DVM, Equine Programs Coordinator with Clemson University Livestock-Poultry Health in Columbia. “This has been a medium year (in number of cases),” she added.

“We make an effort to test horses dying with central nervous system signs because of the possibility not only of EEE, but also to rule out rabies, and, for this year, West Nile virus, as etiological agents,” explained Reece. She added that West Nile virus surveillance has heightened mosquito-borne disease awareness this year in South Carolina (see West Nile update on this page).

The majority of the EEE cases were in young, unvaccinated horses, or in older horses which had not been vaccinated for several years. Affected were pleasure horses and several young Thoroughbreds