09/24/2024
To our clients and followers,
We want to keep you updated on the current Eastern Equine Encephalitis (EEE) situation.
A positive case (middle-aged Belgian female with no known history of vaccinations and previously acquired from the Amish) of EEE has just been confirmed in the Ballston Spa area.
The mare had rapidly deteriorated with acute recumbency and being unresponsive to stimuli. The mare was humanly euthanatized, and blood samples were submitted to Cornell University confirming the suspect.
Here are some aspects of the disease to consider (Source: UC Davis):
Eastern equine encephalitis (EEE) is an extremely rare but serious and often fatal infection that causes encephalitis or inflammation of the brain. It is spread by the bite of a mosquito infected with EEE virus (EEEV). EEEV can also infect a wide range of animals including mammals, birds, reptiles, and amphibians.
Cases are most commonly seen in the southeastern United States, with the mosquito Culiseta melanura as the primary vector (although other species of mosquito can also transmit the virus). Infected horses and humans do not have enough virus in their blood to be contagious to other animals or people. As such, infected individuals do not need to be quarantined.
The disease has a high mortality rate in horses and humans, and, as such, is considered one of the most serious mosquito-borne diseases in the United States.
What are the clinical signs of Eastern equine encephalitis?
The clinical signs of EEE often come on abruptly. These can include depression, anorexia, fever, and lethargy. Neurological signs may include tremors, weakness, ataxia, paralysis, seizures, decreased awareness of surroundings, and recumbency.
How is Eastern equine encephalitis diagnosed?
Eastern equine encephalitis is diagnosed through bloodwork. Testing can include enzyme-linked immunosorbent assay (ELISA) or polymerase chain reaction (PCR) on cerebrospinal fluid (CSF) samples to identify the EEE virus.
How is Eastern equine encephalitis treated?
There is no cure for EEE. Treatment largely consists of supportive care for horses with clinical signs, including intravenous (IV) fluids and anti-inflammatory medications.
What is the prognosis for Eastern equine encephalitis?
The prognosis for horses diagnosed with EEE is poor. The disease has a high mortality rate, with up to 90% of infected horses dying from the disease. Horses with neurologic signs that become unable to stand on their own have the poorest prognosis for survival. Horses that do survive can have permanent brain damage.
How can Eastern equine encephalitis be prevented?
The American Association of Equine Practitioners (AAEP) recommends the EEE vaccine as a core vaccine. Horses should be kept up to date on vaccinations, which are usually administered yearly (boosters may be recommended more frequently in warm climates with year-round mosquito activity). Boosters may be advised when outbreaks occur.
In addition to vaccination, it is important to practice good vector control to protect your horse from EEE. Use insect repellents and keep horses in at night when mosquitoes are most active and shut off barn lights attracting insects. Eliminate mosquito breeding grounds such as standing water, brush piles, and old tires. Stock tanks and water troughs with mosquito-feeding fish.
At this time, we are recommending the following fall vaccine protocol:
1. For horses who have not received the core vaccines incl. the EEE this year to vaccinate them ASAP.
2. For horses who DO NOT travel to booster them with the EEE/WEE, and WNV vaccine (and PHF as needed).
3. For horses who DO travel to booster them with the EEE/WEE, and WNV vaccine as well as Influenza and Rhino (EHV-1+4). The PHF vaccine may be given as needed.
Please call the office with any questions you may have. We are here for you to help keep your horses healthy!
Sincerely,
The Team at the Equine Clinic of Saratoga