Twelve cases of West Nile Virus in horses have been confirmed in Colorado as of Tuesday.
The state Department of Agriculture says most of the cases occurred on the Front Range, but two were in La Plata County and one in Mesa County. Veterinarians advise combating the mosquito-borne illness with equine vaccinations and measures to reduce standing water where the insects breed. Colorado has also had 107 cases of West Nile in humans this year, with six deaths.