Horse Owners Encouraged to Vaccinate for West Nile Virus

June 30, 2023

With mosquito season starting, the state veterinarian of Utah is encouraging horse owners to get their horses vaccinated for the West Nile Virus (WNV) to avoid the risk of being infected by this virus, which affects horses, birds, and humans.

“In the past three years, Utah has had 24 reported cases of West Nile Virus in horses,” said interim state veterinarian, Dr. Amanda Price. “In an effort to keep any more horses from contracting this disease, it is important for horse owners to vaccinate their horses against this virus.”

According to several mosquito abatement programs, parts of Utah are seeing up to five times as many mosquitoes this year compared to a normal year, increasing the chance that horses could be bit and potentially infected.

Signs of WNV in horses include stumbling, a wobbly gait, circling, inability to stand, blindness, fever, and death. Not all horses that become infected will show signs of disease, but one-third of horses that show neurologic signs from WNV will die or be euthanized, and up to 40 percent of those that recover can have long-term issues.  

Any horse that has neurologic signs should be seen by a veterinarian. The disease can be diagnosed through a simple blood test. There is no specific treatment for WNV, but owners and veterinarians can provide supportive care like anti-inflammatory medications or fluids to help the horse recover. Humans and horses cannot spread the disease to each other.

Horse owners should work with their veterinarian to protect their horse against WNV. Horses should be vaccinated for WNV once per year in the spring or early summer before mosquito season starts. Horses that have never been vaccinated before need to get a booster to be fully protected. Owners can also practice good mosquito control, such as removing standing water, cleaning water troughs regularly, using mosquito repellents, and bringing horses inside at dawn and dusk, which are peak mosquito feeding periods.

For more information on how to access a WNV vaccination, horse owners should contact their veterinarian.

Source: Utah Department of Agriculture