West Nile virus found in horse, second state case

BOISE – A Canyon County horse tested positive for West Nile virus, say state health officials who advise the public to take care with mosquitoes.

“The horse is being closely monitored and is fairly stable at this point,” Idaho State Veterinarian Dr. Clarence Siroky said Friday. “WNV is a devastating threat to horses and unfortunately, this horse received no vaccination or booster shots that are essential for the prevention of WNV.”

The positive test comes on the heels of Thursday’s announcement by the Oregon Department of Agriculture that three eastern Oregon horses had tested positive for the virus.

The infection is spread by mosquitoes. The most common symptom in horses is weakness in the hindquarters, indicated by a widened stance, stumbling, leaning to one side and toe-dragging.

“With this Idaho horse case, coupled with yesterday’s reports of West Nile virus in eastern Oregon, we know that West Nile has taken a foothold in our region,” said Dr. Leslie Tengelsen, Idaho deputy state epidemiologist. “People need to take precautions to protect themselves and their families.”

Tengelsen said most people with the virus will not realize they contracted it or will have mild flu-like symptoms. But it can lead to serious illness, especially in people over 50. Common symptoms are headaches, body aches and a mild fever.

August is usually the peak time for mosquito activity. Tengelsen advises people to insect-proof their homes and reduce standing water on their properties where the mosquitoes might breed.

It is the second horse in Idaho that has tested positive, after one diagnosed in June.