Michigan's Second EEE Case of 2019 Confirmed
The Michigan Department of Agriculture and Rural Development (MDARD) confirmed on Aug. 9 that a 19-year-old Standardbred mare presented with clinical signs (high fever, down and unable to get up) of Eastern equine encephalomyelitis (EEE) on Aug. 4 and was euthanized after becoming unable to rise. The mare had not been vaccinated against the disease.

Eastern equine encephalomyelitis is caused by viruses found in wild birds. Mosquitoes that feed on birds infected with EEE can transmit the disease to humans, horses, and other birds. Some birds can harbor the EEE virus without becoming acutely ill, thereby serving as reservoirs for the disease. Horses do not develop high enough levels of these viruses in their blood to be contagious to other animals or humans.

Because of the high mortality rate for horses and humans, EEE is regarded as one of the most serious mosquito-borne diseases in the United States.

Tips for preventing mosquito-borne diseases include:

  • Avoid mosquito bites: Use insect repellent when outdoors, especially from dusk to dawn.
  • Look for EPA-labeled products containing active ingredients, such as DEET, Picaridin (KBR3023), or oil of lemon eucalyptus (p-menthane 3,8-diol).
  • Apply more repellent, according to label instructions, if mosquitoes start to bite.
  • Mosquito-proof homes: Fix or install window and door screens, and cover or eliminate empty containers with standing water where mosquitoes can lay eggs.
  • Protect your horses: Veterinarians recommend commercially available licensed vaccines against EEE for all horses in the U.S. Horses should be vaccinated annually. It’s not too late this year to vaccinate your horses.
  • Use approved insect repellents to protect horses.
  • If possible, put horses in stables, stalls, or barns during the prime mosquito exposure hours of dusk and dawn.
  • Eliminate standing water and drain water troughs, and empty buckets at least weekly.
  • Stock water tanks with fish that consume mosquito larvae (contact your local mosquito control for assistance), or use a mosquito “dunk” available at hardware stores.