First equine case of West Nile virus of 2018 discovered

The Minnesota Board of Animal Health announced on Wednesday that a horse in Pine City, Minn., has contracted the West Nile virus, marking the first equine case in Minnesota in 2018.

The three-year-old miniature horse showed symptoms of the virus on Wednesday, July 27. The horse exhibited profound weakness in his front limbs, tripping and falling and required assistance to stand. The Board of Animal Health reported that the animal is now receiving supportive care.

Dr. Courtney Wheeler, a senior veterinarian at the board and the manager for its equine program, said that the case should spur owners to vaccinate their horses against the disease and to get their horses checked out by a veterinarian if they show signs of the virus.

"Vaccines are very effective in preventing clinical signs of disease, and also preventing disease spread," she said.

Wheeler said that birds are the primary carriers of West Nile virus and that the disease is transmitted via mosquito bites, not from animal to animal. She suggested that preventative measures against mosquitoes, much like the ones used to protect humans, should be applied to horses' living spaces as well.

"One of the best methods of prevention is avoiding exposure to mosquitoes," she said, "so we do recommend that people are cognizant when it comes to horses."

She recommended the following measures to protect horses against mosquitoes:

• Change drinking water regularly
• Avoid having tall grass around barns and stalls
• Drain stagnant water
• Install fans and screens in stables
• Use repellent on horses and people when appropriate

When it comes to the carriers of the virus, Wheeler said that people should be on the lookout for birds exhibiting signs of illness.

Birds sick from the virus may be imbalanced, thin, grounded for long periods of time and generally weak, though some infected birds may not exhibit symptoms.

Wheeler suggested that people report sightings of infected birds to the Minnesota Department of Health and the Metropolitan Mosquito Control District.