Officials have confirmed two horses from Jefferson County with EEE. One horse is reported as recoverying, and one horse was euthanized. | Photo: Wikimedia Commons

On Aug. 11, a 3-year-old Standardbred mare, whose vaccination status was not reported, began showing clinical signs that included drooping lip, fever, being off feed, poor tail tone, drowsiness, vision issues, and severe incoordination. She is recovering.

On Aug. 13, an 18-year-old Standardbred mare presented with high fever, incoordination, falling over, and being off feed. She was euthanized.

EEE 101

Eastern equine encephalomyelitis is caused by the Eastern equine encephalitis virus, for which wild birds are a natural reservoir. Mosquitoes that feed on EEE-infected birds can transmit the virus to humans, horses, and other birds. Horses do not develop high enough levels of these viruses in their blood to be contagious to other animals or humans. Because of the high mortality rate in horses and humans, EEE is regarded as one of the most serious mosquito-borne diseases in the United States