First confirmed case of Eastern Equine Encephalitis (EEE) for 2019

First confirmed case of  EEE for 2019

The Wisconsin Veterinary Diagnostic Laboratory confirmed the first case of Eastern Equine Encephalitis (EEE) in a horse on July 31, 2019.  The 22-year-old quarter horse mare from Barron County had not been vaccinated against EEE, and was euthanized after showing neurological signs, brain tissue tested positive for EEE. 

Vaccines are available to protect against EEE, but there is no treatment once infection occurs.

The first signs for EEE infection in horse are fever, depression and changes in behavior. Clinical signs may include muscle twitches, circling or head pressing behaviors, seizures, inability to swallow, paralysis and convulsions. Many of these clinical signs are overlapping with West Nile Virus (WNV) or Equine herpesvirus type-1 (EHV-1) infection. EEE is almost always fatal in horses and many die within 48 hours of onset of clinical signs. 

The WVDL offers PCR testing for neurologic agents including EEE, WNV and EHV-1.  Please contact our virology section for more details.  

Additional information on EEE and detection and preventative actions for both horses and people, can be found at the following links:

DATCP press release:

UW news release: