Two horses have tested positive for Eastern equine encephalitis (EEE) a mosquito-borne illness caused by a virus that attacks the central nervous system, the Wisconsin Department of Agriculture, Trade and Consumer Protection announced yesterday (Aug. 21).

"Horse owners who have not already had their animals vaccinated this year for EEE and other mosquito-borne diseases should take this as a warning, and those who have vaccinated should check with their veterinarians to see whether a booster is indicated," said State Veterinarian Robert Ehlenfeldt, DVM.

Blood samples were sent to the National Veterinary Services Laboratories in Ames, Iowa, on Aug. 17; the laboratory reported final positive results yesterday. The two horses were located in Clark and Lincoln counties in northern Wisconsin.

"Northern Wisconsin has good mosquito habitat and since it’s been a wet summer up north the mosquito populations are high," Ehlenfeldt said. "We could see a lot more cases if we experience a long fall season