04/22/2026
As Spring begins, Elmore County horse owners should take action to protect their animals from mosquitoes and the diseases that they carry, including West Nile virus (WNv). West Nile virus is present annually in Idaho and it is important for residents to take steps to protect themselves and their horses from mosquito-borne diseases.
Horses are particularly susceptible to WNv as they have no protection from mosquito bites other than what is provided by their owners and horse owners should take steps to minimize their horses’ exposure to mosquito bites and properly vaccinate them against WNv, Western Equine Encephalitis (WEE) and other diseases.
"West Nile virus vaccination continues to be an essential preventive measure and should be given annually to provide an adequate level of protection from the virus,” said Idaho State Veterinarian Dr. Scott Leibsle. “Nearly 98 percent of horses that test positive for WNv are non-vaccinated or under-vaccinated. Horse owners should speak with their veterinarians about the WNv vaccination and other annual core vaccinations as well as how to follow an annual booster schedule. Horses that have been vaccinated for WNv in previous years MUST receive an annual booster; a one-time vaccination is not enough.” It is recommended that an unvaccinated horse receive its first dose of vaccine by April 30, to be properly protected from WNv & WEE.
In addition to vaccination, it is extremely important to take steps to reduce mosquito production in the area immediately around your horse. It is common to find mosquito larvae in water troughs and stock tanks, and all troughs and tanks should be treated with appropriately labelled larval mosquito control products if they cannot be drained and cleaned weekly.
With the onset of Spring and warmer temperatures, people are encouraged to take appropriate precautions to protect themselves and their animals from mosquitoes and the diseases they carry. The following are suggestions to reduce mosquito-borne disease risk:
•Vaccinate horses for WNv, WEE, and other diseases.
•Use EPA registered residual insect sprays on horses, making sure to follow the directions on the container.
•Regularly clean and maintain livestock watering troughs.
•Eliminate or treat all sources of standing water that can be a breeding ground for biting mosquitoes, such as:
o flooded fields
o birdbaths
o wading & swimming pools not in use
o clogged gutters
o old tires.
If it holds water for 7 days, it can produce mosquitoes.
•Wear repellents while outdoors at dusk and dawn when mosquitoes are most active.
•Wear long-sleeved shirts and long pants when in mosquito-infested areas.
•Use mosquito repellents containing DEET, Oil of Lemon Eucalyptus, Picaridin or 2-undecanone, making sure to follow the directions on the container.
•Make sure all screen doors and windows are in good repair and fit tightly.
Additional information on mosquitoes and the diseases they carry can be found at:
Idaho Department of Health and Welfare
https://healthandwelfare.idaho.gov/health-wellness/diseases-conditions/west-nile-virus
U.S. Centers for Disease Control and Prevention
http://www.cdc.gov/ncidod/dvbid/westnile/
Equine Disease Communications Center
http://www.equinediseasecc.org/
National governing body for equestrian sport in the United States. Uniting the equestrian community by ensuring fairness, safety, and enjoyment.
