A study led by researchers at Colorado State University determined that the effects of West Nile virus (WNV) cost equine owners in Colorado and Nebraska more than $1.25 million in 2002, and prevention costs for WNV vaccinations likely exceeded an additional $2.75 million for the equine industry in those states last year. In 2002, Colorado reported 378 and Nebraska reported 1,100 confirmed cases of WNV in equids, a family of animals that includes horses, ponies, donkeys and mules.

The study estimated that the total cost attributed to death or euthanasia of equine WNV cases was $600,660, the estimated revenue lost by owners because of lost-use associated with WNV was $163,659 and the estimated cost attributed to the treatment of equine WNV cases in the two states was $490,844