Five horses in Maine have died of confirmed Eastern equine encephalitis (EEE) and animal health authorities are waiting on test results of another three “suspicious” cases, reported the Maine Department of Health and Human Services (Maine CDC) and the Maine Department of Agriculture’s Animal Health and Industry Division.

EEE is a virus that is transmitted through the bite of an infected mosquito that has picked up the virus by feeding on an infected bird. Humans can also be infected via mosquitoes.

Last month, veterinarians identified EEE in three horses, two in Waldo County and one in Penobscot County. This week, a horse in Cumberland County (Gorham) and another in Waldo County (Unity) have been confirmed to have died of EEE. Two more horses from the Waldo County town of Unity and one from the York County town of Berwick are suspicious, pending test results.

“In all confirmed positive cases thus far, the horses were not up to date on their EEE vaccine or had a questionable vaccination history,” said State Veterinarian Don Hoenig, DVM. “It is important for horse owners to know there is a very effective annual vaccine for EEE and they should be sure their horses are current on this vaccine