A horse in Yakima County has been euthanized due to West Nile virus.
Officials from the Washington state Department of Agriculture said the 2 year-old gelding was pastured near the city of Grandview and had not traveled out of the area. As well, the animal was not vaccinated against the disease.
The Washington Animal Disease Diagnostic Laboratory in Pullman reported the positive test results to the state veterinarian’s office.
The virus 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.
No human cases of West Nile virus have been confirmed in Washington in 2012. According to the Centers for Disease Control and Prevention, 1,118 human cases have been reported in 38 states this year.
The disease 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.
Washington led the nation with 72 West Nile virus cases in horses in 2009, but no equine cases were detected in the past two years. Officials continue to urge owners to vaccinate their horses against the disease.
Veterinarians who learn of potential cases in horses or other animals should call 360-902-1881.