Sign Up for Newsletters

West Nile Virus AlertBy Kentucky Equine Research Staff · July 15, 2013

In early July, West Nile virus (WNV) was found in a mosquito in southwestern Ohio. Birds, horses, and humans can be infected with WNV if they are bitten by a mosquito that is carrying the virus, which causes severe or fatal inflammation of the brain in some cases.

Signs of WNV infection in horses include incoordination, weakness, stumbling, twitching of muscles and lips, and depressed attitude. Even with veterinary care, up to one-third of infected horses die or are euthanized.

Horses can be vaccinated against WNV. Effective protection is gained by a primary vaccination with a second dose given four to six weeks later. After the first year, a single booster should be given annually.

To minimize the risk of mosquito bites for horses, use insect repellent sprays and keep stable lights turned off from dusk to dawn. Survey the property to find and eliminate all sources of standing water where mosquitoes can lay their eggs. This includes water that collects in buckets, old tires, and puddles from rain or drainage. Ponds and water troughs can be treated to prevent mosquitoes from breeding.