October 10, 2025

Eastern equine encephalitis confirmed in northern Indiana

By Erica Quinlan
In 2020, EEE infections were detected in four horses in LaGrange, Kosciusko and LaPorte counties. One human case of EEE occurred in a LaPorte County resident in 2020. In 2019, EEE infection was detected in 14 horses in Elkhart and LaGrange counties. The infected horses were either not vaccinated or overdue on vaccination. One fatal human case of EEE occurred in Elkhart County in 2019, and 10 human cases occurred in southern Michigan, six of which were fatal.

In 2020, EEE infections were detected in four horses in LaGrange, Kosciusko and LaPorte counties. One human case of EEE occurred in a LaPorte County resident in 2020. In 2019, EEE infection was detected in 14 horses in Elkhart and LaGrange counties. The infected horses were either not vaccinated or overdue on vaccination. One fatal human case of EEE occurred in Elkhart County in 2019, and 10 human cases occurred in southern Michigan, six of which were fatal. (USDA photo/Jennifer Strickland)

INDIANAPOLIS — The first case of eastern equine encephalitis in Indiana since 2020 was confirmed by the state Board of Animal Health.

The horse was a 6-year-old, unvaccinated gelding in LaGrange County.

What Is It?

EEE is often called “sleeping sickness” because it causes infected animals to enter a coma.

Other clinical signs may include listlessness, high fever, head pressing, lateral recumbency and seizures. Horses that develop it rarely survive.

According to BOAH, the EEE virus is maintained in the bird population and is transmitted by mosquitoes that breed in freshwater wetlands.

The best way to manage EEE is to vaccinate and minimize exposure to mosquitoes.

Vaccination

Horse owners should work with their veterinarian to determine a regimen that includes selecting the best vaccine product given in a timely way.

Vaccinations are generally administered in the spring for season-long protection. Combination products will prevent several mosquito-borne viruses in a single dose.

Minimize Exposure

Prevention is also accomplished by reducing exposure to mosquito bites.

Eliminate sources of standing water where the pests breed — even small amounts of water in old tires, clogged gutters, puddles or stagnant water troughs can harbor insects.

Keep livestock confined indoors with good ventilation and fans during peak mosquito activity, from dusk to dawn.

If using an insect repellent, select a product labeled for use on that species.

If you suspect your horse may have EEE, contact a veterinarian right away.

Animal WelfareHorsesLivestock
Erica Quinlan

Erica Quinlan

Field Editor