A 22-year-old Quarter Horse mare in Barron County has been euthanized after contracting EEE. | Photo: Wikimedia Commons

Veterinarians euthanized the unvaccinated mare after she showed neurologic signs and became recumbent.

“From an animal welfare perspective, vaccinating horses against EEE and West Nile virus (WNV) is necessary to prevent the suffering that occurs once the horse contracts the virus,” said DATCP Equine Program Veterinarian Julie McGwin, DVM, in an Aug. 2 statement. “While the number of cases of EEE and WNV were down last year compared to the previous year, it is heartbreaking for all involved to see any animal suffer through deteriorating health conditions caused by these viruses. We encourage all horse owners to work with their veterinarian to get their horses vaccinated against these diseases.”

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 viruses without becoming acutely ill, thereby serving as reservoirs for the disease. Horses don’t 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