MADISON, Wis. (AP) -- An outbreak of Eastern equine encephalitis is expanding in Wisconsin.

State Veterinarian Robert Ehlenfeldt says 25 cases of the mosquito-borne disease have been confirmed in Wisconsin since mid-August, mostly in the north-central part of the state.

Ehlenfeldt advises horse owners to call a veterinarian if their horses show any signs of central nervous system disease. Those include loss of appetite, dropping eyelids and lower lip, aimless wandering and circling, and sometimes paralysis.

The disease has a mortality rate of 90 percent or higher. So far the disease has been detected in Price, Lincoln, Taylor, Clark, Marathon and Dunn counties.

Ehlenfeldt expects more cases to be confirmed. He says warm weather forecast next week might mean mosquitoes are more active.

In 2001, 69 cases of the disease were confirmed in Wisconsin.