The Virginia Department of Agriculture and Consumer Services (VDACS) has confirmed the first case of Eastern Equine Encephalitis (EEE) in a horse this year. The horse, a two-year-old Arabian male from Suffolk, was vaccinated for EEE and West Nile Virus (WNV) more than a year ago but was not revaccinated this year.
Last year Virginia had no reported cases of EEE in horses or other livestock. The disease has a mortality rate of around 80 percent, so prevention is a key part of equine health. Generally, EEE is transmitted by mosquitoes. Prevention methods include vaccination, destroying standing water breeding sites for mosquitoes, using insect repellents and removing animals from mosquito-infested areas during peak biting times, usually dusk to dawn.
In an April 2014 press release, Dr. Richard Wilkes, VDACS’ State Veterinarian, encouraged horse owners to work with their veterinarians to plan a vaccination schedule that would protect their horses from EEE and West Nile Virus. Available vaccines are generally effective in drastically reducing the incidence of both EEE and WNV in horses. For the vaccine to be effective it must be handled and administered properly and be given at least two weeks before the horse is exposed to the virus. Additionally, to stimulate full immunity, horses must be vaccinated twice, about 30 days apart, the first year of vaccination. The vaccines are effective for six to 12 months, so horses should be revaccinated at least annually. In an area where the disease occurs frequently, such as southeast and Tidewater Virginia, most veterinarians recommend vaccination every six months.
For more information, please contact the Office of the State Veterinarian at 804.692.0601 or consult your local veterinarian.
Director of Communications
Virginia Department of Agriculture and Consumer Services
102 Governor Street
Richmond VA 23219