A two-year-old gelding contracted West Nile virus in Washington, marking the first case confirmed in the state since 2009, the Washington State Department of Agriculture reported yesterday.
The horse was pastured near Grandview, Wash., and had no history of travel out of the area. The horse was not vaccinated for West Nile virus and was euthanized after testing positive for the virus, as confirmed by the Washington Animal Disease Diagnostic Laboratory in Pullman.
Washington led the nation with 72 cases of West Nile virus in 2009 but reported no cases in 2010 or 2011, the WSDA reported.
Though weather conditions over the past year have led to an ideal environment for mosquito breeding in Washington, complacency may have been the biggest factor in this case, said Jason Kelly, a WSDA spokesman.
“When you don’t have detection for a couple of years, it’s not at the top of everyone’s mind,” Kelly said.
Most horses do not become ill as a result of contracting West Nile virus, but it is fatal in about one-third of those that show clinical signs. Symptoms can include loss of coordination, loss of appetite, confusion, fever, stiffness and muscle weakness, particularly in the hindquarters.
Washington’s state veterinarian urged owners to vaccinate their horses against the virus, and veterinarians who learn of potential cases of the disease should contact the state veterinarian at 360-902-1881.