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Kentucky Ag Commissioner Encourages Horse Owners to Vaccinate For West Nile Virus

Lexington, Kentucky - A large mosquito infestation is expected in Kentucky this year after a rainy spring. Mosquitoes can carry West Nile Virus, and Agriculture Commissioner Richie Farmer encourages horse owners to talk to their veterinarians about vaccinating their horses for the virus.

"Since 2003, no horses known to have been properly vaccinated have gotten West Nile in Kentucky," Commissioner Farmer said. "Kentucky had 513 equine cases of West Nile in 2002, the first full year the virus was active in Kentucky, and 137 horses died. Since then, vaccination has become much more common, and the number of cases of West Nile has fallen sharply."

Historically, West Nile Virus begins showing up in Kentucky horses in July. The number of cases usually increases throughout the summer before peaking in mid-September.

West Nile was first identified in Kentucky’s equine population in the fall of 2001. A total of 683 horses have been diagnosed with the disease in Kentucky in the past 10 years.

The virus mainly affects horses, humans and birds, but dogs and cats also are susceptible. It causes encephalitis, or inflammation of the brain. About two out of every three horses that become infected survive.

Commissioner Farmer recommends that property owners take action to eliminate areas of standing water, which serves as a breeding ground for mosquitoes. Property owners are advised to:

Change water every week in bird baths, pet bowls, wading pools and watering troughs;

Keep ponds free of vegetation and stocked with fish; and

Destroy or dispose of tin cans, old tires, buckets, unused plastic swimming pools or other containers that collect and hold water.

The Kentucky Department of Agriculture sprays for mosquitoes when asked by local officials. The insecticides are rigorously tested and degrade quickly. To see a spraying schedule and for more information on the program, go to the Department’s website,, click on Pest and Weed Programs, and click on Mosquito Control.

The risk of severe illness in humans due to West Nile Virus is slight. Young children, adults over age 50, and those with weak immune systems are at greatest risk for contracting the virus. To reduce the chance of infection, the Kentucky Department for Public Health advises people to stay indoors at dawn, early evening, and dusk if possible; wear light-colored, long-sleeved shirts, long pants and a hat when outdoors; and apply mosquito repellent to exposed skin containing DEET (N, N-diethyl-m-toluamide), permethrin, picardin or oil of lemon eucalyptus.

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