Ocean County Horse Euthanized After Contracting Eastern Equine Encephalitis: Authorities

An Ocean County horse has been euthanized after testing positive for Eastern Equine Encephalitis (EEE), a serious, mosquito-borne illness in horses, state Agriculture officials announced Tuesday.

The 1-year-old mare had only been vaccinated recently but had not received a booster shot, according to a news release from the state Department of Agriculture. The horse was euthanized Aug. 26, the release said.

The horse is the third in the last month that has died as the result of the illness; the news release said a 3-year-old Morris County gelding was euthanized on Aug. 23 after testing positive for the disease. That horse had not been vaccinated, according to the news release.

The announcement of the euthanizations follows on the heels of the report of a death from the disease of another Morris County horse earlier this month.

EEE causes inflammation of the brain tissue and has a significantly higher risk of death in horses than West Nile Virus infection. West Nile virus is a viral disease that affects horses’ neurological system. The disease is transmitted by mosquito bite. The virus cycles between birds and mosquitoes, with horses and humans being incidental hosts. EEE infections in horses are not a significant risk factor for human infection because horses (like humans) are considered to be "dead-end" hosts for the virus, the news release said.

“Horse owners need to be vigilant in vaccinating their animals against diseases spread by mosquitoes,” New Jersey Secretary of Agriculture Douglas H. Fisher said. “Vaccinated animals are much less likely to contract deadly diseases such as EEE and West Nile Virus.”

Effective equine vaccines for EEE and WNV are available commercially. Horse owners should contact their veterinarians if their horses are not already up-to-date on their vaccinations against both EEE and WNV.

For more information about EEE in horses, visit the New Jersey Department of Agriculture web site by clicking here.

EEE and West Nile virus, like other viral diseases affecting horses’ neurological system, must be reported to the state veterinarian at 609-671-6400 within 48 hours of diagnosis. The New Jersey Animal Health Diagnostic Laboratory is available to assist with EEE and WNV testing and can be reached at 609-406-6999 or via email – jerseyvetlab@ag.state.nj.us.

A horse in a field in Monmouth County. Karen Wall photo