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MDARD Confirms First Case of West Nile Virus for 2024 in an Eaton County Horse

Preventing mosquito bites is the first step to preventing mosquito-borne disease

LANSING, MI — Today, the Michigan Department of Agriculture and Rural Development is reporting Michigan's first case of West Nile virus (WNV) for 2024 in a domestic animal. The case occurred in a three-year-old Percheron colt from Eaton County. The horse was unvaccinated against the disease. This detection highlights the importance for Michiganders to continue taking precautions to protect their animals and themselves from mosquito bites.

"On July 21, 2024, the horse became ill with a lack of coordination, facial muscle twitches, and being down with an inability to rise. Subsequent testing revealed the animal was positive for WNV,"  said State Veterinarian Dr. Nora Wineland, DVM, MS, DACVPM. "The key to protecting any domestic animal species from WNV or other mosquito-borne diseases is to safeguard them from mosquitoes and work with your veterinarian to vaccinate as appropriate."

Even though WNV typically circulates between birds and mosquitoes, mosquitoes can also transmit the disease to people and other animals, especially horses. In Michigan, the disease is usually seen every summer through early fall. Mosquito-borne diseases, like WNV, are not spread by horse-to-horse or horse-to-human contact.

This year in Michigan, WNV has been detected in 49 mosquito pools, 19 wild birds, and one human. Eastern equine encephalitis, another mosquito-borne disease affecting both animals and humans, was detected in a horse earlier this month. For the latest information on cases of mosquito-borne diseases in Michigan, please visit Michigan.gov/EmergingDiseases for weekly summaries.

To prevent the occurrence of mosquito-borne diseases in horses and other animals, owners can:

  • Talk to a veterinarian about vaccinating horses against WNV, Eastern equine encephalitis (EEE), 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 repellant on animals 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. Please contact MDARD at 800-292-3939 for more details.

Michiganders can stay healthy by using simple, effective strategies to protect themselves and their families. The following steps are recommended to avoid mosquito-borne diseases:

  • 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.

For more information about WNV, please visit www.Michigan.gov/WNV.

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