What is West Nile Virus?
From the Centers for Disease Control:
West Nile Virus is a flavivirus commonly found in Africa, West Asia, and the Middle East. It is closely related to St. Louis encephalitis virus which is also found in the United States. The virus can infect humans, birds, mosquitoes, horses and some other mammals.
And from the Washington State Department of Health:
West Nile virus is a serious illness that can affect people, horses, birds, and other animals. It first appeared in the United States in 1999 on the East Coast. Since that time, it has spread rapidly across the country. In Washington, the first cases of people becoming ill from West Nile virus were reported in 2006.
Is West Nile Virus very prevalent in Washington?
From the Washington State Department of Agriculture:
Last year, 179 WNV cases were reported nationwide. Washington led the nation with 41 horses testing positive for the disease: 26 horses in Yakima County; 10 horses in Grant County; four horses in Benton County; and one horse in Kittitas County.
Why is West Nile Virus especially dangerous for equines?
State veterinarian Leonard Eldridge writes:
WNV is fatal in about one-third of all horses that contract it, although most horses do not become ill and show no symptoms at all. Those that do become ill show signs such as loss of coordination, loss of appetite, confusion, fever, stiffness, and muscle weakness particularly in the hindquarters.
What can I do to protect my horse/donkey/mule?
Dr. Eldridge continues:
Horse owners should contact your veterinarian for advice for vaccination recommendations and WNV control measures. The vaccine requires two doses the first year of vaccination two to four weeks apart. Immunity will not be achieved until three to five weeks after the second vaccination, so it’s important to avoid waiting until mosquito season is in full swing. An annual booster dose should be administered prior to the start of the mosquito season.
For more information about WNV and tips on how to protect yourself, check out these pamphlets: