Gloucester Co. Horse Contracts Mosquito-Borne Illness, First In 2023

GLOUCESTER COUNTY, NJ — A horse in Gloucester County was euthanized after recently contracting Eastern Equine Encephalitis, a mosquito-borne illness and New Jersey's first reported case of 2023.

In a news release, the New Jersey Department of Agriculture said it was unclear whether the 1-year-old colt was vaccinated against the disease, which affects the neurological system and causes inflammation of brain tissue.

The colt was humanely euthanized on Sept. 17, officials said.

So far this year, New Jersey officials have recorded no other cases of Eastern Equine Encephalitis (EEE) or West Nile virus, another mosquito-borne disease that affects a horse’s neurological system. Animals infected with EEE often show signs of fever, depression and changes in behavior. Other symptoms include impaired vision, muscle twitches, circling, head-pressing behaviors, the inability to swallow, paralysis and convulsions.

EEE and West Nile virus can affect both horses and humans; however, horses don't pose a significant infection risk to humans because they are considered "dead-end" hosts, health officials said.

While the mosquito population in New Jersey remains near the five-year average, the first EEE-positive mosquito pool was detected in Gloucester County this year. Ongoing surveillance also indicates West Nile virus activity is high among mosquitos this year compared to the five-year average, state officials said.

Livestock owners are strongly encouraged to vaccinate horses against West Nile virus, EEE and other mosquito-borne diseases. Owners should contact their veterinarians if their horses are not up to date on vaccinations.

“We continue to encourage horse owners to be vigilant in vaccinating their animals against these diseases spread by mosquitoes,” New Jersey Assistant Secretary of Agriculture Joseph Atchison said in a statement. “Vaccinated animals are much less likely to contract deadly diseases."

More information on EEE is available on the state Department of Agriculture's website.