Michigan's first 2026 case of Eastern equine encephalitis in domestic animal found in Clare County

Michigan's first case of Eastern equine encephalitis (EEE) in a domestic animal in 2026 has been detected in a horse in Clare County. 

State health officials said the mosquito-borne illness was found in an under-vaccinated 1-year-old quarter horse colt from Clare County. 

The colt was taken to a specialty hospital, but was humanely euthanized, according to officials. 

While the Clare County horse is the first case of EEE detected in a domestic animal in 2026, there has been one human case found in a Roscommon County resident earlier this summer. It's the first human case in Michigan since 2021. 

"These detections clearly indicate EEE, as well as other possible mosquito-borne viruses, are circulating in the state's mosquito population. Preventing mosquito bites is crucial to prevent mosquito-borne diseases in our animals and families," said state veterinarian Dr. Nora Wineland.

Like other mosquito-borne illnesses, Michigan health officials say EEE cannot be passed by horse-to-horse or horse-to-human contact. Cases are typically seen in the state's late summer and early fall. 

"With the recent case of EEE in a Roscommon County resident and now this new detection, it is crucial that Michigan residents take precautions against mosquito bites," said Dr. Natasha Bagdasarian, the state's chief medical executive. "EEE is one of the most dangerous mosquito-borne diseases in the U.S., with a 30% fatality rate among people who become ill."

How you can protect animals from mosquito-borne illnesses

• Talk to a veterinarian about vaccinating horses against EEE, WNV, and other mosquito-borne diseases.
• Eliminate standing water—i.e., fill in puddles, repair eaves, and change the water in buckets and bowls at least once a day.
• Place livestock in a barn under fans (as mosquitoes are not strong flyers) and pets inside the home during peak mosquito activity from dusk to dawn.
• Use an insect repellent on animals that is approved for the species.
• Contact a veterinarian if an animal shows signs of illness. If a Michigan animal is suspected of having EEE or WNV, funding is available under an arbovirus grant to cover these testing costs. 

How you can protect yourself against mosquito-borne diseases

MDARD recommends the following tips to protect you and your family from mosquito-borne illnesses like EEE.

• Apply insect repellents that contain the active ingredient DEET or other EPA-approved products to exposed skin or clothing. Always follow the manufacturer's directions for use.
• Wear light-colored, long-sleeved shirts and long pants when outdoors. Apply insect repellent to clothing to help prevent bites.
• Maintain window and door screening to help keep mosquitoes outside.
• Empty water from mosquito breeding sites around the home, such as buckets, unused kiddie pools, old tires, and other water-holding containers where mosquitoes can lay eggs.