Mosquitoes that feed on EEE-infected birds can transmit the virus to humans, horses, and other birds. | Photo: iStock

Officials at the Wisconsin Department of Agriculture, Trade, and Consumer Protection (WDATCP) have confirmed that three horses have died from Eastern equine encephalomyelitis (EEE). One was located in each of three counties: Oconto, Oneida, and Shawano.

The Oconto County horse, a yearling Quarter Horse gelding that was undervaccinated, started showing clinical signs on Sept. 19. Signs included fever, depression, anorexia (loss of appetite), ataxia (loss of muscle control), teeth grinding, reluctance to move, muscle fasciculation (twitching) of the head and neck, left facial paralysis, aniscoria (differences in pupil size), and lack of pupillary reflex. He was euthanized.

On Sept. 22, an unvaccinated 14-year-old Quarter Horse mare in Oneida County began experiencing signs that included aniscoria, facial twitching, recumbency (down and unable to rise), and slow pupillary reflex. She was confirmed positive on Sept. 30 and was euthanized