Fight the Bite: Protect Against West Nile Virus in Nevada

Two Possible Infections Found in Horses in Clark and Churchill Counties


Jessica Fagundes
Sparks, NV - August 16, 2016

The Nevada Department of Agriculture (NDA) reports results of West Nile Virus (WNV) infections in two horses; one in Churchill County and one in Clark County. While horses are not a source of human infection, a horse with WNV is an indication that other horses and humans in the area are at risk through mosquito bites.

Every year, the NDA monitors WNV, and other diseases carried by mosquitos (also known as arboviral), very closely for the protection of public health and safety and the agriculture industry. 

"It's important for horse owners to protect their animals from West Nile Virus through vaccination," the NDA's state veterinarian, Dr. JJ Goicoechea, said. "Vaccinations, in conjunction with practices that reduce exposure to mosquitos, are very effective in protecting horses from WNV. WNV can cause severe neurologic disease in horses."


In addition to WNV, the Animal Disease Laboratory at the NDA tests for two other prevalent arboviral diseases: Saint Louis Encephalitis Virus and Western Equine Encephalitis Virus. All three can cause severe disease and death in humans.

The Animal Disease Lab has tested more than 2,000 mosquito pools from all Nevada counties since May of this year. To date, the laboratory identified WNV positive mosquito pools from Clark, Churchill, Elko, Douglas, Lincoln and Washoe Counties. Mosquitos tested positive for Saint Lewis Encephalitis in Clark and White Pine Counties.

West Nile Virus has been prevalent in Nevada since 2004, while Saint Louis Encephalitis and Western Equine Encephalitis have been widespread in the western United States for decades. 

Mosquito season is expected to end with the first frost in October. However, while the current temperatures persist, all Nevada residents should take precautions such as eliminating mosquito-breeding sites around houses and barns, using insect repellents to fight the bite and keeping horses vaccinated against WNV and Western Equine Encephalitis.


The Nevada Department of Agriculture promotes a business climate that is fair, economically viable and encourages environmental stewardship that serves to protect food, fiber and human health and safety through effective service and education. The NDA includes the five divisions of Administration, Animal Industry, Consumer Equitability, Food and Nutrition and Plant Industry.