WNV, West Nile Virus, West Nile
Birds carrying the West Nile Virus are bitten by mosquitoes that transfer the virus to horses, other birds and other mammals including humans. Birds in the crow and jay family are thought to be the most common carriers, although some other species including waterfowl may be carriers of WNV. WNV is not transferred from horse to horse or horse to human.
Horses that have contracted the WNV may have elevated temperature, listlessness, apathy, weakness, poor coordination, partial or full paralysis, nervousness, lethargy or drowsiness, and seizures. Many horses are infected with WNV and show few, if any symptoms.
WNV can be fatal, but many horses recover fully and are able to take on a normal workload. Others may show some signs of weakness or neurological damage.
Drug, vitamin, and fluid therapies may help although there is no specific course of treatment. Veterinarian supervision is essential.
Although vaccination for WNV has been controversial in the horse industry it is the best preventative against infection. Horse owners should take steps to reducing mosquitoes and protect their horse and themselves from being bitten. Depending on the prevalence of WNV vaccine may be administered once or several times per season. Discuss the appropriate schedule and vaccine options with your veterinarian.