Fifth WNV Case in Kentucky

A new case of West Nile virus (WNV) was confirmed today (Aug. 24) in Nelson County, Kentucky, according to Rusty Ford, Equine Programs Manager in the Kentucky State Veterinarian's office. This is the second WNV case confirmed in that county, and the fifth confirmed in the state this year.

The yearling Morgan colt was euthanatized. Onset of his clinical signs was Aug. 10.

Of the five Kentucky cases confirmed this year, none were vaccinated, and four of the animals either died or were euthanatized. The Kentucky Department of Agriculture's web site will be updated to reflect these additional cases--visit

West Nile virus (WNV) was first identified in October 1999 in New York. Clinical signs for WNV include:

  • Flu-like signs, where the horse seems mildly anorexic and depressed.
  • Fine and coarse muscle and skin fasciculations (twitching).
  • Hyperesthesia, or 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).
  • "Spinal" signs, including asymmetrical weakness. Some horses show asymmetrical or symmetrical ataxia (incoordination on one or both sides, respectively).

Other signs include paralysis of the lips, facial muscles, or tongue. Some victims also have a head tilt and difficulty swallowing.

Vaccination and mosquito control are the best preventative measures.

About the Author

Kimberly S. Brown

Kimberly S. Brown was the Publisher/Editor of The Horse: Your Guide To Equine Health Care from June 2008 to March 2010, and she served in various positions at Blood-Horse Publications since 1980.

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