West Nile virus

Washington Ag Today May 19, 2009 The first confirmed case of West Nile virus in a Washington horse last year wasn't reported until August 1st. But that doesn't mean horse owners should wait to get their animals vaccinated against a disease that can be fatal one-third of the time. Mike Louisell with the Washington State Department of Agriculture explains why the state vet is advocating vaccination now. Louisell: "Because for first time horses getting the shot you need two doses two to four weeks apart. And then immunity does not become achieved until about three to five weeks later after the second vaccination. So in that sense August is not that far away." Horses previously vaccinated may need a booster so check with your veterinarian. Louisell says Washington led the nation last year with 41 horses testing positive for West Nile. Most of the animals did not have current vaccinations. Louisell: "About 12 horses had to be put down by veterinarians." Last year Yakima County had the most confirmed cases of the disease in horses, 26. That was followed by 10 horses in Grant County, four horses in Benton County and one in Kittitas. In previous years West Nile virus has also been detected in Western Washington. West Nile virus is spread by mosquitoes that have fed on infected birds. Veterinarians who learn of potential WNV cases in horses or other animals should contact the State Veterinarian's Office at (360) 902-1881. I'm Bob Hoff and that's Washington Ag Today on the Northwest Ag Information Network.