2020 Equine West Nile Virus (WNV) Update: Twelfth Confirmed Equine WNV Cases

On September 21, 2020, a vaccinated 1-year-old Thoroughbred filly in Stanislaus County, displaying neurologic signs, was confirmed positive for West Nile Virus. The fillyis alive and recovering. This is the twelfth confirmed case of equine WNV in California in 2020.

For 2020, a total of twelve (12) horses have been confirmed positive for West Nile Virus in California.  The positive horses were located in Amador (1),  Butte (1), Glenn (1), Merced (1), Riverside (2), San Bernardino (1), San Joaquin (2), and Stanislaus (3) counties. Seven (7) horses were unvaccinated, four (4) horses had unknown vaccine history and one (1) was vaccinated. Nine (9) horses are alive, one (1) horse died, and two (2) horses were 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.