Kentucky's Second Equine WNV Case of 2012 Confirmed

Kentucky animal health officials have confirmed the commonwealth's second case of equine West Nile virus (WNV) in 2012, according to a statement from Kentucky Equine Programs Manager E.S. "Rusty" Ford.

The affected horse--an 18-year-old Tennessee Walking Horse gelding from Laurel County--had no WNV vaccination history, Ford's statement said. The horse began to show signs of disease on the night of Aug. 6, when he exhibited mild ataxia (incoordination) that worsened throughout the following day, the statement said. On Aug. 8, the horse became recumbent and disoriented, at which point he was euthanized.

Ford's statement said that PCR test results confirmed the diagnosis on Monday (Aug. 13) evening.

Officials confirmed Kentucky's first equine WNV case of 2012 on Aug. 3; the affected horse--an unvaccinated yearling Thoroughbred filly from Henderson County--was euthanized Aug. 1.

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 USDA Animal and Plant Health Inspection Service reported 83 cases of WNV in U.S. horses in 2011; only one case was reported that 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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