The Horse | Equine West Nile Virus Activity Ripe in 2012
So far in 2012, according to the United States Geological Survey's Disease Maps, 77 cases of equine WNV have been reported in the following states, as of Aug. 14: Arizona, California, Colorado, Indiana, Iowa, Kentucky, Louisiana, Michigan, Mississippi, Missouri, New Jersey, New Mexico, North Dakota, Oklahoma, Pennsylvania, South Carolina, South Dakota, Texas, and Wyoming.
Louisiana--which did not report any equine WNV cases last year--has confirmed the most cases so far this year with 21, according to statistics from the Louisiana Department of Health & Hospitals.
Clinical signs for WNV include flulike signs, where the horse seems mildly anorexic and depressed; fine and coarse muscle and skin fasciculation (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%.