A 10-year old mare from north Pasco is the second case of equine West Nile virus reported in Washington this year. The horse was euthanized.
The horse was not vaccinated for the disease, and had not left the state. West Nile is potentially fatal in infected equines, other mammals and birds. The Washington State University’s Animal Disease Diagnostic Laboratory in Pullman reported the positive test results to the State Veterinarian’s Office earlier this week.
The only other confirmed case of West Nile virus in a Washington horse this year was reported in late September for a horse pastured in Outlook.
“A killing frost will reduce the likelihood of further cases for the year,” said Acting State Veterinarian Paul Kohrs.
West Nile virus is spread by mosquitoes that have fed on infected birds. The disease sickens people, horses, birds and other animals, but it does not spread from horses to people or other animals.
According to the Centers for Disease Control and Prevention, 1,135 human cases have been reported nationwide this year.