Fourth Kentucky Horse Tests Positive for WNV

Fourth Kentucky Horse Tests Positive for WNV

WNV is a viral disease transmitted to horses by infected mosquitoes.


The Kentucky State Veterinarian's office announced Sept. 20 that a Christian County horse has tested positive for West Nile virus (WNV).

"Results of diagnostic results reported earlier this afternoon by Murray State University's Breathitt Veterinary Center confirmed a diagnosis of West Nile virus affecting a fourth Kentucky horse this season," read the statement from Kentucky Equine Programs manager E.S. "Rusty" Ford.

Ford's statement relayed that on Sept. 18 the 8-year-old Percheron/Standardbred cross mare—who has no WNV vaccination history—began showing clinical signs of disease including lethargy and mild hind limb ataxia.

As of Sept. 20, the mare was reportedly showing signs of improvement, Ford's statement said.

The most recent case is the fourth equine WNV case confirmed this year in the commonwealth. All of the WNV-affected horses in Kentucky are reportedly recovering.

Additionally in Kentucky, a 10-year-old unvaccinated Tennessee Walking Horse gelding residing in Hart County succumbed to another mosquito-borne disease—Eastern equine encephalitis (EEE)—in August. He was the first horse to test positive for EEE in Kentucky since 2008.

WNV is a viral disease 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.

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