Return to WSDA Home  |  Return to News Release Page

Two West Nile virus horse cases reported: Adams and Benton counties

OLYMPIA — West Nile virus (WNV), a potentially fatal disease in equines, has been confirmed in two horses, bringing this year's total to five confirmed cases of horses testing positive for the disease, the Washington State Department of Agriculture (WSDA) announced today.

A five-year-old Quarter horse gelding in Othello, has made a slight recovery. The Othello horse was not vaccinated for WNV and is the first horse confirmed to have contracted the disease in Adams County this year. A four-year-old Quarter horse gelding in Kennewick has been euthanized due to the illness. The horse had not been vaccinated.

Previously announced cases, beginning July 24, were confirmed in horses located in Ellensburg, Toppenish and Prosser. The Washington Animal Disease Diagnostic Laboratory in Pullman reported the test results to the State Veterinarian's Office.

WNV is spread by mosquitoes that have fed on an infected bird. The disease can sicken people, horses, many types of birds, and other animals. It is not spread from horses to other animals.

Last year, Washington had confirmed cases of WNV in horses in Yakima, Grant, Benton and Kittitas counties. In previous years, WNV horse cases have been detected in Western Washington as well. Virtually all of the horses that acquired West Nile virus last year were not current with vaccinations.

WNV is fatal in about one-third of all horses that show clinical signs, although most horses do not become ill and show no symptoms at all. Those that do become ill display loss of coordination, loss of appetite, confusion, fever, stiffness, and muscle weakness, particularly in the hindquarters.

Veterinarians who learn of potential WNV cases in horses or other animals should contact the State Veterinarian's Office at (360) 902-1881.

Additional information on WNV can be found at the state Department of Health Web site at www.doh.wa.gov/WNV and at the U.S. Department of Agriculture Web site at www.aphis.usda.gov/vs/nahss/equine/wnv.

# # #