Over the last several months, the Utah Department of Agriculture and Food has reported 20 confirmed cases of West Nile Virus in horses in 14 different counties across the state.
The virus, which usually moves between birds and mosquitos, can be transmitted to mammals when infected mosquitos feed on most commonly horses and humans.
Utah’s Assistant State Veterinarian Dr. Sabo said the state is seeing an increase in positive cases in horses, particularly late in the season.
“We're right in the middle of what is our normal mosquito season. So we usually think of like July to October,” said Sabo. “We do have more cases this year than we've seen historically.”
The first case was reported in late July. Two cases were reported last week — one in San Juan County and the other in Summit County.
“The signs that are associated are mostly associated with that brain and spinal cord damage. And so horses will often be weak or be stumbling, they'll have little muscle twitches, often in the face and neck,” Sabo explained. “Unfortunately, the case fatality rate sits around 33% and horses who are treated, about 40% of them, unfortunately, still have lingering signs over six months after treatment.”
Sabo said the best way to prevent infection is by vaccinating, usually in the spring, before mosquito season but given case increases, if a horse has not received a West Nile vaccine, now is a good time.
“We have vaccination for horses that is quite effective in preventing both infection and the signs of the disease. There's four different vaccines that livestock owners can choose from, and they can purchase those both at Farm Stores and through their veterinarian," Sabo said.
Sabo also recommends other preventative measures like decreasing standing water, cleaning out buckets and tubs, and keeping the barn as unattractive to birds as possible.
