South Carolina has reported an additional case of Eastern Equine Encephalitis (EEE) in a horse, the 12th case of 2016. The state veterinarian received the report on the most recent case out of Florence County on Friday.


The case was an unvaccinated, 5 month old Paint. The colt did not survive. This is the first confirmed case in Florence County this year.

EEE is a mosquito-transmitted disease that is much more severe than West Nile Virus (WNV).  The mortality rate in horses from WNV is reported at around 30%, while the rate for EEE is almost 90%.  Infected mosquitoes are the primary source for EEE.

The virus causes inflammation or swelling of the brain and spinal cord.  General symptoms include central nervous system signs such as: head pressing, convulsions, lack of response to facial stimulation, fever above 103 degrees, ataxia, paralysis, anorexia, depression and stupor.  Other symptoms may include irregular gait, teeth grinding, in-coordination, circling, and staggering.  All symptoms may not be exhibited by an infected horse.