On Oct. 11, Ohio Department of Agriculture (ODA) officials confirmed Ohio’s fifth equine case of Eastern equine encephalomyelitis (EEE). The unvaccinated 2-year-old Friesian gelding from Ashtabula County first showed clinical signs (ataxia, depression, fever, unresponsiveness, and inability to swallow) indicative of EEE on Oct. 3. He was subsequently euthanized.

This is Ohio’s fifth EEE-positive horse for 2019, and Ashtabula County’s third.

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