On Aug. 30, an unvaccinated Lapeer County horse started experiencing clinical signs of Eastern equine encephalomyelitis (EEE), including ataxia (incoordination), blindness, lowered head, leaning, and weakness and was subsequently euthanized. | Photo: Wikimedia Commons

On Aug. 30, an unvaccinated Lapeer County horse started experiencing clinical signs of Eastern equine encephalomyelitis (EEE), including ataxia (incoordination), blindness, lowered head, leaning, and weakness and was subsequently euthanized. The Michigan Department of Agriculture and Rural Development (MDARD) confirmed the 10-year-old Haflinger mare positive for EEE.

EEE 101

Eastern equine encephalomyelitis is caused by the Eastern equine encephalomyelitis 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