State Veterinarian issues warning to horse owners

    AUGUSTA — As mosquito season approaches, horse owners should make sure their animals are up to date on their vaccination for Eastern Equine Encephalitis (EEE).     “Last year Maine experienced an unprecedented and widespread outbreak of this highly fatal, but very preventable, disease,” said Dr. Don Hoenig, Maine State Veterinarian. In the late summer and fall of 2009, 15 horses and one llama died in central and southern Maine from EEE. Additionally, three pheasant flocks in southern Maine were humanely euphemized due to infection with the virus.
    EEE is a preventable, but usually fatal, viral disease in horses. Unfortunately, this disease can also affect humans if they are bitten by mosquitoes that carry the virus. The mosquitoes are infected by feeding on infected wild birds, in which the virus replicates and which act as natural “reservoirs” for the disease. Horses will show central nervous system signs, such as stumbling or poor balance, unusual behavior, or severe lethargy. Head pressing, circling, tremors, and eventual coma and seizures are also frequently seen. Horses are very susceptible to the virus, but don’t “concentrate” it, as do birds or mosquitoes, so they are not considered a risk for transmitting the virus into mosquitoes or for directly infecting humans.
    This disease is easily preventable by routine vaccination. Many vaccines are available and they can either be administered by the owner’s veterinarian or purchased at feed or pet stores for owner administration to their own horses. Often EEE vaccination can be given in combination with Tetanus, another important equine vaccination. Generally, vaccination for EEE is carried out annually, but Dr. Hoenig urges horse owners to consult with their practicing veterinarian to decide whether a booster is needed now, due to the current increased risk.
    EEE is a reportable disease in Maine. More information can be found on the Maine Department of Agriculture’s website at: http://www.maine.gov/agriculture/ahi/diseases/index.html#eee, or by contacting the Division of Animal Health and Industry at 287-3701.