Five Montana Horses Diagnosed with WNV

West Nile virus (WNV) has been confirmed in horses in five Montana counties, state Livestock Department officials said Wednesday (Aug. 16).

Horses in Cascade, Glacier, Phillips and Yellowstone counties and a second horse in Flathead County were diagnosed recently, said Dr. Jeanne Rankin, assistant state veterinarian.

The first confirmed case, a 2-year-old stallion in Flathead County, had not been vaccinated and was euthanized on July 22.

Ages of the animals infected this year range from a 1-year-old filly to a 7-year-old stallion. None were vaccinated and all are recovering.

''Historically, this is about the time of year when the first cases of West Nile virus appear,'' Rankin said. ''We have had six cases reported so far this year and we can expect to see this run through September and into October.''

Rankin said it is not too late to vaccinate horses against West Nile virus.

''With the West Nile virus season possible into late October, there is still time to complete the recommended two initial vaccinations, which are given three to six weeks apart,'' she said.

Since the first confirmed case of West Nile virus in horses in the state in 2002, Montana has had 354 cases, 333 of them involving unvaccinated horses. There have been 118 deaths.

The worst year was 2003, with 193 confirmed cases stretching into late October.

West Nile virus is transmitted by mosquitoes.

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The Associated Press

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