Texas animal health officials are cautioning owners that horses in that state have tested positive for Eastern equine encephalitis (EEE) and West Nile virus (WNV).

On July 30, the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) reported that a horse in Jefferson County, on the southeastern Gulf Coast, tested positive for WNV.

“This is the third confirmed (equine) case of WNV in Texas in 2015, and as with other positive cases, the horse was not vaccinated for WNV,” a TVMDL statement said. “Clinical signs alerted the horse’s owners to a potential problem: mild depression and muscle fasiculations.”

Clinical signs for WNV include flulike signs, where the horse seems mildly anorexic and depressed; fine and coarse muscle and skin fasciculations (twitching); hyperesthesia (hypersensitivity to touch and sound); changes in mentation (mentality), when horses look like they are daydreaming or "just not with it"; occasional drowsiness; propulsive walking (driving or pushing forward, often without control); and "spinal" signs, including asymmetrical weakness. Some horses show asymmetrical or symmetrical ataxia. Equine mortality rate can be as high as 30-40%