West Nile in Minnesota: Horse owners encouraged to vaccinate their animals

Horse owners beware – a deadly virus has been detected in horses in Minnesota.

The Minnesota Board of Animal Health on Friday reported West Nile virus was detected in two horses in Kandiyohi County this week. One horse, a 1-year-old quarter-horse colt that was unvaccinated, died from illness-related complications. The other horse, a 21-year-old mare, had recently received the West Nile virus booster dose prior to the infection, allowing them to recover. 

The cases were at different farms, and the virus is seemingly being spread by mosquitos in the same county. The virus cannot be spread to animals or people by contact with infected horses.

In response to the identified cases, veterinarians are pleading for horse owners to get their horses vaccinated as soon as possible.

"Vaccination is the best way to protect horses from West Nile virus," said Dr. Heather Damico, senior veterinarian in charge of equine. "Historically, a lot of the reported cases we deal with in horses are either unvaccinated or under vaccinated, which means they didn’t receive their annual booster shot. Vaccines can prevent infection or reduce severity of disease if the horse is infected."

West Nile virus is regularly found in Minnesota during the summer largely due to birds who serve as the primary host of the disease. The virus can be passed between infected birds and mosquitoes. Once infected, mosquitoes can transmit the virus to horses or people. 

Symptoms of the virus include inflammation of the brain and spinal cord. Infected horses could also show neurological symptoms including muscle tremors and incoordination.

Other ways that people can prevent West Nile virus cases are changing water weekly, mowing long grass, removing any stagnant water where mosquitoes could breed, maintaining screens and keeping windows closed, and using mosquito repellent.

Summer is a high-risk time of year for West Nile virus transmission. The Metropolitan Mosquito Control District has already reported West Nile virus has been detected in routine mosquito samples conducted in several Twin Cities metro counties this summer. People are encouraged to act and get vaccinations for their horses now. Additionally, the Minnesota Board of Animal Health requests that all positive test results for West Nile virus disease be reported immediately.