Equine West Nile Virus case confirmed in Weld County

A 3-year-old gelding residing in Weld County has been diagnosed with West Nile Virus and is now recovering. The horse developed neurological symptoms in late July, including weakness, stumbling and poor muscle control. The gelding’s vaccine status is unknown. This is Colorado’s first confirmed equine WNV case in 2022.

The first human case of WNV this year was confirmed in Delta County on July 29 with four additional human cases confirmed, one in Montrose County, Arapahoe County, an additional case in Delta County and one in Boulder County. Mosquito pools in Adams, Boulder, Larimer, Mesa, and Weld counties have tested positive for WNV this summer.

“West Nile Virus is actively circulating in Colorado and continues to pose a risk to people and unvaccinated equines,” said Colorado State Veterinarian Dr. Maggie Baldwin. “Vaccines are an effective prevention tool for West Nile Virus in horses and owners should work with their veterinarians to determine the appropriate vaccination schedule for their horses.”

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.