GRAND ISLAND, Neb. (AP) — The Central District Health Department officials are encouraging people to protect not only themselves from West Nile virus, but their horses, too.

The department, based in Grand Island, says horses should be properly vaccinated for the mosquito-borne illness.

Horse vaccinations are only effective if given before exposure to West Nile. Adequate vaccination requires two doses, administered three to six weeks apart. Full protection doesn’t develop until four to six weeks after the second dose.

The most common signs of West Nile infection in horses include stumbling, weak limbs, partial paralysis, muscle twitching and, in some cases, death.