Since first being recognized in the United States in 1999, West Nile virus (WNV) has posed a serious threat to horses and humans alike. In the equine population, the virus is transmitted when a mosquito takes a blood meal from a bird infected with WNV, then feeds on a horse.
While many horses exposed to WNV experience no signs of illness, the virus can cause inflammation of the brain and spinal cord. In some cases, especially in older horses, WNV can be fatal.
Prevention is the key to reducing your horse's risk of contracting WNV. Follow these guidelines from the American Association of Equine Practitioners to protect your horse against WNV:
1. Consider vaccinating your horse against the disease. In February 2003, a vaccine was licensed by the USDA's Center for Veterinary Biologics for use in healthy horses as an aid in the prevention of the disease. Talk with your veterinarian about the most appropriate vaccination schedule for your horse.
2. Eliminate potential mosquito breeding sites. Dispose of old receptacles, tires and containers and eliminate areas of standing water.
3. Thoroughly clean livestock watering troughs at least monthly.
4. Use larvicides to control mosquito populations when it's not possible to eliminate particular breeding sites. Such action should only be taken, however, in consultation with your local mosquito control authority.
5. Keep your horse indoors during the peak mosquito activity periods of dusk to dawn.
6. Screen stalls, if possible, or at least install fans over your horse to help deter mosquitoes.
7. Avoid turning on lights inside the stable during the evening or overnight.
8. Use insect repellents on your horse designed to repel mosquitoes. This can help reduce the chance of your? horse being bitten.
9. Remove any birds, including chickens, located in or close to a stable.
10. Don't forget to protect yourself, as well. When outdoors in the evening, wear clothing that covers your skin, and apply plenty of mosquito repellent.
For more information about the virus, ask your equine veterinarian for the "West Nile Virus" brochure, produced by the AAEP in conjunction with Bayer HealthCare Animal Health, an AAEP Educational Partner. For additional information about WNV, click here.
Reprinted with permission from the American Association of Equine Practitioners.