A Monroe County horse has tested positive for Wisconsin’s first case of Eastern equine encephalitis (EEE) in 2021. The results were confirmed on August 11th by the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) and the Wisconsin Veterinary Diagnostic Laboratory.
The unvaccinated two-year-old crossbred gelding was euthanized after showing symptoms of the disease. Horse owners are strongly encouraged to vaccinate their horses against EEE and West Nile virus (WNV), which are both transmitted by mosquitoes.
WNV and EEE may cause encephalitis or inflammation of the brain. Symptoms of encephalitis in horses include depression, loss of appetite, drooping eyelids and lower lip, fever, weakness, twitching, paralysis or lack of coordination, aimless wandering, circling, and blindness. Horses may also go down, be unable to rise, exhibit seizures, or become unresponsive. Horse owners should contact their veterinarian if they observe any of these signs.
EEE is fatal in more than 90% of equine cases, and WNV is fatal in 30-40% of cases. In 2020, Wisconsin confirmed 26 cases of EEE and no cases of WNV.
EEE is not contagious between horses, but an infected horse means the virus is in Wisconsin’s mosquito population. Besides vaccination, limiting exposure to mosquitoes will help control these diseases.
