Kentucky Confirms Second Equine WNV Case of 2013

Kentucky Confirms Second Equine WNV Case of 2013

This viral disease is transmitted to horses by infected mosquitoes.


The Kentucky State Veterinarian's office announced Aug. 31 that a Hopkins County horse has tested positive for West Nile virus (WNV).

"Diagnostic test results reported Friday (Aug. 30) evening by Murray State University's Breathitt Veterinary Center confirms a diagnosis of West Nile virus having affected a second horse in Western Kentucky," according to the statement from Kentucky Equine Programs Manager E.S. "Rusty" Ford.

Ford's statement relayed that on Aug. 27 the 10-year-old Quarter Horse mare—who has no WNV vaccination history—began showing clinical signs of disease; she was down, but able to rise when encouraged, and showed an ataxic (incoordinated) gait when walking.

As of Aug. 30 the attending veterinarian reported that the horse was stable with some improvement, Ford's statement said.

The most recent case is the second equine WNV case confirmed this year in the commonwealth. On Aug. 13, a 5-year-old unvaccinated Quarter Horse mare residing in Edmonson County tested positive for the disease and is recovering, Ford's most recent statement indicated. Last week a 10-year-old unvaccinated Tennessee Walking Horse gelding residing in Hart County succumbed to another mosquito-borne disease—Eastern equine encephalitis (EEE). He was the first horse to test positive for EEE in Kentucky since 2008.

This viral disease is transmitted to horses by 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%.

The United States Department of Agriculture Animal and Plant Health Inspection Service reported 627 cases of WNV in U.S. horses in 2012; 13 cases were reported last year in Kentucky.

About the Author

Erica Larson, News Editor

Erica Larson, news editor, holds a degree in journalism with an external specialty in equine science from Michigan State University in East Lansing. A Massachusetts native, she grew up in the saddle and has dabbled in a variety of disciplines including foxhunting, saddle seat, and mounted games. Currently, Erica competes in eventing with her OTTB, Dorado.

Stay on top of the most recent Horse Health news with FREE weekly newsletters from Learn More