Officials at the Ohio Department of Agriculture confirmed on Sept. 13 that a 3-year-old Standardbred gelding tested positive for Eastern equine encephalomyelitis (EEE) in Portage County, Ohio. | Photo: Wikimedia Commons

Officials at the Ohio Department of Agriculture (ODA) confirmed on Sept. 13 that a 3-year-old Standardbred gelding tested positive for Eastern equine encephalomyelitis (EEE) in Portage County, Ohio. The horse, which was previously vaccinated in the spring with no booster administered, began showing clinical signs of recumbency (down and unable to rise), hind limb paraparesis (partial paralysis of lower limbs), faint pulses in both hind limbs, and limbs cool to the touch on Aug. 29. The horse was subsequently euthanized.

ODA officials stated this is Ohio’s third EEE case in 2019.

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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