Six cases of potentially fatal Eastern Encephalitis confirmed in Texas, one in Liberty County
Posted: Friday, July 31, 2015 7:39 pm
By Vanesa Brashier
Horse owners in Texas are being encouraged to have their animals vaccinated after six cases of Equine Eastern Encephalitis (EEE) have been found in the state this summer.
One case involved a horse on Carter Loop in Tarkington where the animal died despite expensive, life-saving measures. According to Dr. Bud Alldredge, owner of Alldredge Veterinary Hospital in Tarkington, another case is suspected of EEE in Liberty County but cannot be proven. Other cases have been reported in Jasper and Jefferson counties.
Equine Eastern Encephalitis is transmitted to horses by mosquitoes carrying the virus. The risk increases in the summertime as mosquito populations are thriving and active.
“Horses cannot transfer it to another horse. People can also contract the disease from an infected mosquito but it’s rare,” said Alldredge. “People and horses are considered dead-end hosts for the virus because they cannot spread it to others.”
According to the Centers for Disease Control, only 4-5 percent of people bitten by an infected mosquito contract the virus. However, for those who do, there is no treatment and antibiotics are not effective. Approximately one-third of all persons who contract the virus die and many of those who live have lifelong brain damage.
“The mortality rate for horses is higher with Eastern Encephalitis than with Western Encephalitis,” Alldredge said. “The old saying when I was a kid was, ‘If a horse lives, it had Western; if it dies, it had Eastern.’”
Symptoms in an infected horse are generally seen within 1-3 weeks of the time it was bitten by an infected mosquito. These symptoms include:
Dull or listless behavior
Muscle tremors
Head pressing such as the animal pushing its head against walls, fences or other objects
Ataxia (muscle weakness) in the back lags
“The biggest sign is ataxia in the back legs. They get weak and wobbly. They act like they don’t know where their legs are and have partial paralysis,” Alldredge said.
Besides avoiding standing water and using mosquito and fly sprays to control the mosquito population, the most effective way to avoid the virus in horses is through vaccines, which are around $60-70. The prevention is a VEWT shot, which covers Venezuela Encephalitis, Eastern Encephalitis, Western Encephalitis and Tetanus. Some vaccines also include prevention of Rhino Virus, influenza and West Nile.
Once a horse has the virus, it is too late to receive the vaccine. After a vaccine is given, the horse is not immediately protected as it could take a few days to a week to work its way through its body.
Among the horse owner community, word about the EEE case in Liberty County appears to be spreading. Alldredge says he has seen a sharp increase in the number of people having their horses vaccinated.
“I have been to only one public place in the last couple of weeks when I wasn’t asked about it,” he said.
For more information on EEE and other horse-related illnesses, consult your veterinarian or go online to the Texas Veterinary Association’s website at https://tvma.azurewebsites.net/, or the Centers for Disease Control website at www.cdc.gov.