Weld County horse diagnosed with West Nile Virus

A horse residing in Weld County has been diagnosed with West Nile Virus, marking Colorado’s first confirmed equine WNV case in 2021. The horse, which had not been vaccinated against WNV, developed acute neurological signs on July 24 and is currently recovering.

“Vaccines have shown to be an effective prevention tool for West Nile Virus in horses and Horse owners should work with their veterinarian to determine the appropriate vaccination schedule for their horses,” said State Veterinarian Dr. Maggie Baldwin. “West Nile Virus is one of the AAEP core vaccinations for horses, along with others such as rabies, tetanus, and eastern and western encephalomyelitis. All of these vaccines are important to protect the health of Colorado’s equine herds.”

Horses vaccinated for WNV in past years will need an annual booster. If a horse has not been vaccinated in previous years, it will need the two-shot vaccination series. Visit the AAEP website at aaep.org for a comprehensive list of vaccination recommendations.

In addition to vaccinations, horse owners should also work diligently to reduce mosquito populations and their possible breeding areas where horses are located. Recommendations include removing stagnant water sources, using mosquito repellents, and keeping animals inside during the bugs’ feeding times, typically early in the morning and evening.

Any time a horse displays clinical signs consistent with neurologic disease, a complete veterinary examination is warranted. All infectious or contagious equine neurologic diseases are reportable to the Colorado State Veterinarian’s Office at 303-869-9130. A chart of reportable animal diseases in Colorado can be found on the CDA website at ag.colorado.gov/animals/livestock-health.