BROOKSVILLE — The Hernando County Health Department received confirmation this week that a horse in the southeastern part of the county tested positive for Eastern equine encephalitis and was euthanized due to the effects of the virus.
According to county health officials, the horse — on property near Hayman and Neff Lake roads — was the 15th in the state and the first in Hernando County this year known to have contracted the disease, commonly known as EEE, which is carried by mosquitoes. Most of the other deaths were confined to several counties in North Florida.
Environmental health director Al Gray said that it has been four years since the disease was last documented in Hernando by the Florida Department of Agriculture and Consumer Services.
"We first saw EEE in Hernando County in 2001 (in wild birds). In 2002, 20 horses were diagnosed here in Hernando," Gray said. "About that time, the vaccine became available, and we didn't see any more positive horses until 2009. We have not seen any other cases until now."
Considered to be fairly rare since the introduction of modern vaccines, the virus is almost always fatal in infected horses, said Dr. Sarah Quatman of Blue Skies Equine Veterinary Services in Dade City.
"Once the symptoms appear, it's usually too late to do much other than comfort the animal," Quatman said.
Signs in EEE-infected horses can vary, but usually begin with fever, depression and listlessness, and quickly progress to more serious neurological signs such as incoordination, stumbling and head drop.
Once a horse becomes infected, there is no effective treatment. Death usually occurs within 48 to 72 hours of the first indication of illness.
Humans cannot contract EEE from horses, but, like horses, they can become infected through mosquitoes, Gray said. So far, no human cases have been reported in Hernando County. However, in 2010 the disease was blamed for four deaths in Florida, including two people in Hillsborough County.
Those who live in or visit wooded habitats, as well as people who work outside or participate in outdoor recreational activities in areas where the disease is circulating, have greater exposure to potentially infected mosquitoes.
Hernando's mosquito control staff is monitoring the area near where the horse lived for mosquito activity, and is reminding residents to be vigilant about mosquito bite prevention.
Quatman said that horse owners are encouraged to have their animals vaccinated every six months to provide protection from the disease. A vaccination typically costs between $25 and $35.
Logan Neill can be reached at firstname.lastname@example.org or (352) 848-1435.