A 2-year-old horse in Benton County, Washington, has been confirmed to have West Nile virus (WNV), as reported by the assistant state veterinarian. The horse was not vaccinated against the virus.
EDCC Health Watch is a marketing program of Equine Network that uses information from the Equine Disease Communication Center (EDCC) to generate and share verified equine disease updates. The EDCC is an independent nonprofit organization funded by industry donations to provide accessible infectious disease information.
WNV 101
West Nile virus is transmitted to horses through bites from infected mosquitoes. While not all infected horses display symptoms, those that do may show:
- Flulike signs, such as mild anorexia and depression;
- Muscle and skin twitching;
- Hypersensitivity to touch and sound;
- Changes in mental activity;
- Occasional drowsiness;
- Propulsive walking;
- Spinal weakness; and
- Ataxia.
There is no cure for West Nile virus in horses. However, some may recover with supportive care, although mortality rates can be high. Vaccination has been shown to be an effective prevention method against WNV. Horses previously vaccinated need an annual booster, while unvaccinated horses require a two-shot series.
Apart from vaccination, owners can reduce the risk of WNV by eliminating mosquito breeding grounds, keeping horses indoors during peak feeding times, and using approved mosquito repellents.