EEE Reports Prompt Horse Vaccination Push

Recent reports of several horses dying from Eastern equine encephalitis (EEE) serve as a reminder that horse owners should make sure their horses are vaccinated.

"We've always recommended that horse owners in Oklahoma vaccinate for it as a preventive measure," said Carolynn MacAllister, DVM, Oklahoma State University Cooperative Extension veterinarian.

EEE is spread by mosquitoes. Veterinarians recommend that horses be vaccinated to protect against mosquito-borne diseases such as West Nile virus and Eastern and Western equine encephalitis as part of their routine health care program.

"It takes a week to 10 days after vaccination for a horse to develop protective antibodies," MacAllister said. "Booster shots should be administered as directed to maintain the highest level of protection."

Clinical signs of EEE include confusion, erratic behavior, staggering, and even collapsing. A blood test is needed to confirm the diagnosis. Some infected horses will survive provided they get timely and appropriate supportive care.

"An infected horse will not spread EEE, WEE or West Nile virus to humans," MacAllister said. "Humans can be infected with these diseases, but the source of the virus is not horses. Rather, an infected horse acts as a sentinel that the disease may be in your area. Mosquitoes are the culprit."

Dave Freeman, MS, PhD, Oklahoma State University Cooperative Extension equine specialist, said there are management steps that horse owners should take in addition to vaccination of animals.

"Police your property and drain sources of stagnant water where mosquitoes can breed," he said. "Make sure to use approved products that kill mosquito larvae in water sources such as troughs, ponds, and even fountains, if applicable, taking care to always follow label directions. Consider sheltering horses at night."

And don't forget the personal management: Avoid being outside at night or at dawn, when mosquitoes are most active, and wear protective clothing with long sleeves and pants whenever possible. Protect yourself from mosquito bites with a repellant containing DEET.

In addition to Texas, EEE cases have been reported this year in North Carolina, Florida, Louisiana, Missouri, and Virginia.

Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.