On July 31 the Massachusetts Department of Public Health (MDPH) announced the first equine case of Eastern equine encephalitis (EEE) this year. The affected horse was stabled in Belchertown and is that town’s second EEE infected horse in two years.

“Today’s finding significantly raises our concern for the area. It’s important that people in high risk areas protect themselves from getting bitten by mosquitoes,” said MDPH State Public Health Veterinarian Catherine Brown, DVM, MSc.

A viral disease, EEE affects the central nervous system and is transmitted to horses by infected mosquitoes. Its fatality rate in horses is 75-95%. The course of EEE can be swift, with death occurring two to three days after onset of clinical signs despite intensive care. Horses that survive might have long-lasting impairments and neurologic problems. Clinical signs of EEE include moderate to high fever, depression, lack of appetite, cranial nerve deficits (facial paralysis, tongue weakness, difficulty swallowing), behavioral changes (aggression, self-mutilation, or drowsiness), gait abnormalities, or severe central nervous system signs, such as head-pressing, circling, blindness, and seizures.

Massachusetts confirmed five cases of EEE in horses in 2012. Nationwide, 209 equine cases were confirmed