A recent jump in the number of Eastern Equine Encephalitis cases has state health officials urging horse owners to take precautions against the virus.
Six cases of Eastern Equine Encephalitis have been confirmed in North Carolina this year, according to a release from the N.C. Department of Agriculture and Consumer Services. In the last month alone there have been confirmed cases in Richmond, Onslow, Duplin, Craven and Carteret counties.
“Last year we didn’t reach six cases of EEE in the state until October,” Agriculture Commissioner Steve Troxler said in a statement. “The excess rain this year, or just an increase in mosquito population, could be attributing to the early onset of cases.”
Eastern Equine Encephalitis is a mosquito transmitted disease that can cause severe inflammation of the brain and spinal cord in horses and other equines. As the name suggests, EEE most commonly occurs in the Eastern United States and Canada. The virus affects the nervous system, causing fever, depression and changes in behavior in affected animals.
Emily Gilnette, an equine veterinarian with Eastern Equine Associates in New Bern, said the number of cases seen in North Carolina so far this year is unusually high.
“Sometimes we don’t even see this many cases in an entire year,” she said.
Gilnette said she was unsure why the number of EEE cases had spiked over the last several months. She said recent heavy rainfall may have contributed to an increase in the mosquito population, raising the risk for area horses.
Gilnette said there are several EEE warning signs equine owners should look out for. Animals suffering from the virus will initially become lethargic and show less interest in food and may exhibit circling or head pressing behaviors. As the virus progresses, the animal will begin to stumble and take on a vacant “nobody’s home” appearance. During the final stages, they will be unable to stand and may fall or lay down. The virus eventually causes paralysis and, in most cases, death.
Unfortunately, said Gilnette, EEE has a 98 to 99 percent mortality rate in horses.
“We can treat them to decrease the inflammation in their central nervous systems, but they rarely recover,” she explained.
Gilnette recommended that equine owners keep their animals’ vaccinations up to date. She said not doing so could make them more susceptible to EEE. In each of the reported cases in North Carolina this year, the animals had no records of vaccinations or were not vaccinated by a licensed veterinarian.
“If their vaccinations aren’t up to date, then potentially the animal’s immune system won't be able to protect them,” she said.
A combination vaccine for both EEE and West Nile virus is available that initially requires two doses, 30 days apart, for horses, mules and donkeys that have no prior vaccination history.
Gilnette said treating horses with fly spray, moving them indoors when possible and eliminating any areas of standing water in the vicinity can also reduce the chances of animals becoming infected with the virus.
Although it is possible for humans to contract EEE, only a few cases are reported in the United States each year, according to the Centers for Disease Control and Prevention. No human cases of EEE have been identified in North Carolina in 2018.