California Department of Food and Agriculture
Number Confirmed: 1;
Number Euthanized: 1;
Horse 1:
Age: 6; Gender: Stallion; Breed: Andalusian; Onset of Clinical Signs: 7/22/2026; Clinical Signs: fever, grade 4 ataxia, muscle fasciculations; Confirmation Date: 7/29/2026; Horse Status: Euthanized; Vaccination Status: Unvaccinated;
Comments: The second (2nd) case of West Nile Virus in California in 2026 was confirmed in San Joaquin County. On July 29, 2026, an unvaccinated 6-year-old Andalusian stallion in San Joaquin County displaying neurologic signs was confirmed positive for West Nile Virus. The stallion was euthanized due to severity of clinical signs.