Fifth Case of West Nile Virus in
Utah Horse Reported

Tests conducted on a horse in Duchesne County have confirmed that the animal is infected with West Nile Virus (WNV). This is the fifth case of West Nile virus in a Utah horse this year. The horse is the latest equine animal to be diagnosed with the disease. It is unknown whether the horse was vaccinated for WNV or not. Four other horses that contracted the disease this year had NOT been vaccinated. The animal joins one in Weber County and three in Utah County to contract WNV this year.

WNV is not transmissible from horses to humans.

Human safety measures

The Utah Department of Health and the Weber Morgan Health Department are asking people to insect-proof their homes, and if they are in areas that have mosquitoes, wear protective clothing and use insect repellant containing DEET.

People can install or repair screens around their home and inspect for standing water that can provide mosquito-breeding habitat. This includes old tires, decorative ponds or birdbaths. There is no human vaccine for WNV.

Equine safety measures

The Utah Department of Agriculture and Food (UDAF) is strongly advising horse owners throughout the state to continue to protect their animals by vaccinating them for the West Nile Virus if they haven’t done so already. The UDAF also advises all Utahns to take necessary precautions to protect themselves from WNV.

The UDAF has been advising horse owners to administer two vaccination shots for the past several weeks. It is now advisable to administer a booster shot for added protection. The WNV vaccine is available from local veterinarians.

Utah now joins Wyoming, Colorado, New Mexico, Arizona, Nevada, California and Idaho as states reporting WNV in horses.

The most common sign of West Nile virus in horses is weakness, usually in the hindquarters. Weakness may be indicated by a widened stance, stumbling, leaning to one side and toe dragging. In extreme cases, paralysis may follow. Fever is sometimes evident, as are depression and fearfulness. WNV causes encephalitis and affects the central nervous system.

Horse owners who suspect West Nile viral infection of their animal should contact their veterinarian immediately. Approximately 1/3 of horses that show signs of the illness will die. Eighty percent of WNV in horses occurs in the months of August and September. Horse owners who have not already done so should contact their veterinarian and have their horses vaccinated, though vaccination after exposure may not protect the horse against the disease.

The equine vaccine requires two doses and takes approximately five weeks to offer protection from the disease. Once vaccinated, yearly booster shots are necessary.

Horse owners can protect their animals by applying approved repellants to the animals and by controlling mosquitoes and mosquito breeding areas. Horse owners may also protect the animals by putting them in the barn or other enclosed structures.

For more information about the West Nile Virus, please visit the Utah Department of Agriculture and Food’s web page at: http://ag.utah.gov or the Utah Department of Health’s web page: http://health.utah.gov.