The Kentucky State Veterinarian’s office has announced Aug. 20 that a Jefferson County horse has tested positive for West Nile virus (WNV), the first confirmed case in the commonwealth this year.

In a statement Kentucky Equine Programs manager E.S. "Rusty" Ford relayed that the 5-year-old Tennessee Walking Horse mare with no history of vaccination presented with acute ataxia (incoordination), lip paresis, and the inability to move backwards on Aug. 12. The horse is alive and reported to be showing improvement on Aug. 20.

In 2014 Kentucky confirmed four cases of WNV in horses on four premises.

West Nile is transmitted to horses via bites from infected mosquitoes. 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 somnolence (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%