RALEIGH – Two horses have been confirmed this week as having died after contracting Eastern Equine Encephalomyelitis within the past two weeks. EEE is a mosquito-borne disease that is preventable in equine by vaccination.
The unvaccinated horses – an 18-month-old Paint from Carteret County and a 3-year-old Quarter horse from Bladen County – exhibited signs of generalized weakness, stumbling, depression and inability to stand or eat. The Carteret County horse was euthanized July 21, and the Bladen County horse died Aug. 2.
They are the first reported cases of EEE in horses in North Carolina this year. Earlier this summer, New Hanover County officials reported that the disease was found in a sentinel chicken flock. The state recorded 15 EEE cases in horses in 2013.
“If your horses exhibit any symptoms of EEE, contact your veterinarian immediately,” said State Veterinarian David Marshall. “Several serious contagious diseases, such as West Nile virus, equine herpes virus and rabies, have similar symptoms and should be ruled out.”
EEE causes inflammation or swelling of the brain and spinal cord and is usually fatal. Symptoms include impaired vision, aimless wandering, head pressing, circling, inability to swallow, irregular staggering gait, paralysis, convulsions and death. Once a horse has been bitten by an infected mosquito, it may take three to 10 days for signs of the disease to appear.
Marshall recommends that equine owners talk to their veterinarians about an effective vaccination protocol to protect horses from EEE and another mosquito-borne disease, West Nile virus. The vaccinations initially require two shots, 30 days apart, for horses, mules and donkeys that have no prior vaccination history. Marshall recommends a booster shot every six months.
Mosquitoes can breed in any puddle that lasts for more than four days, so removing any source of standing water can reduce the chance of exposing animals to WNV or EEE. Keeping horses in stalls at night, using insect screens and fans and turning off lights after dusk can also help reduce exposure to mosquitoes. Insect repellants can be effective if used according to manufacturers’ instructions.
People, horses and birds can become infected from a bite by a mosquito carrying the diseases, but there is no evidence that horses can transmit the viruses to other horses, birds or people through direct contact.