2021 Equine West Nile Virus (WNV) Update: Thirteenth Confirmed Equine WNV Cases

On October 6, 2021, an unvaccinated 5-year-old Arabian gelding displaying neurologic signs in San Joaquin County, was confirmed positive for West Nile Virus. The gelding is alive and recovering. This is the thirteenth confirmed case of equine WNV in California in 2021.

For 2021, a total of thirteen (13) horses have been confirmed positive for West Nile Virus in California.  The positive horses were located in Amador County (1), Fresno County (2), Kings County (1), Merced County (1), Sacramento County (2), San Joaquin County (3), Stanislaus County (1), and Yuba County (2). Nine (9) horses were unvaccinated, two (2) horses had unknown vaccine history and two (2) were vaccinated. Eleven (11) horses are alive, one (1) horse died, and one (1) horse was euthanized. CDFA continually monitors and investigates equine neurologic cases for the presence of WNV in California. CDFA urges horse owners to consult their veterinarian concerning a WNV vaccination program to ensure maximum protection of their horses.