Disease Alerts

Number Confirmed: 1; 
Number Exposed: 4; 
Facility Type: Private Facility; 

Horse 1: 
Age: 17; Gender: Gelding; Breed: Quarter Horse (QH); Usage: Pleasure Riding; Onset of Clinical Signs: 9/2/2026; Clinical Signs: mild to moderate acute ataxia and pyrexia improving with supportive care; Confirmation Date: 9/3/2026; Horse Status: Recovering; Vaccination Status: Unvaccinated;

Number Confirmed: 1; 
Number Exposed: Unknown; 
Facility Type: Stable; 

Horse 1: 
Age: 2; Gender: Mare; Breed: Quarter Horse (QH); Usage: Farm/Ranch; Onset of Clinical Signs: 9/2/2026; Clinical Signs: Ataxia Anorexia Abnormal Mentation; Confirmation Date: 9/9/2026; Horse Status: Affected And Alive; Vaccination Status: Status Unknown;

Number Confirmed: 1; 
Number Exposed: Unknown; 
Facility Type: Private Facility; 

Horse 1: 
Age: 4; Gender: Gelding; Breed: Quarter Horse (QH); Usage: Farm/Ranch; Onset of Clinical Signs: 9/2/2026; Clinical Signs: Weakness Ataxia Teeth Grinding Fasciculation; Confirmation Date: 9/9/2026; Horse Status: Affected And Alive; Vaccination Status: Unvaccinated;

Number Confirmed: 1; 
Number Exposed: Unknown; 
Facility Type: Farm; 

Horse 1: 
Age: 19; Gender: Gelding; Breed: Draft; Onset of Clinical Signs: 8/25/2026; Clinical Signs: This gelding developed acute neurologic signs (ataxia, falling down) on Aug 25, 2026 and was euthanized. Serum was positive for WNV IgM.; Horse Status: Euthanized; Vaccination Status: Unvaccinated;

Comments: This is the third confirmed case of equine WNV in Ontario this year . To see past and present WNV cases in Ontario go to: https://www.oahn.ca/resources/ontario-equine-disease-alerts/ and enter the disease surveillance portal.;

Number Confirmed: 1; 
Number Euthanized: 1; 
Comments: This is the 1st confirmed case of WNV for Florida in 2026.;

Number Confirmed: 1; 

Horse 1: 
Age: 10; Gender: Gelding; Breed: Paint; Onset of Clinical Signs: 8/28/2026; Clinical Signs: ataxia, muscle fasciculations, hypermetric, hypersensitivity; Confirmation Date: 9/3/2026; Horse Status: Affected And Alive; Vaccination Status: Vaccinated;

Comments: The tenth (10th) equine case of West Nile Virus in California in 2026 was confirmed in Sutter County. On September 3, 2026, a 10-year-old vaccinated Paint gelding in Sutter County displaying neurologic signs was confirmed positive for West Nile Virus. The gelding is alive and recovering. The gelding currently resides in Contra Costa County but was exposed in Sutter County.;

Number Confirmed: 1; 

Horse 1: 
Age: 3; Gender: Mare; Breed: Oldenburg; Onset of Clinical Signs: 8/27/2026; Clinical Signs: ataxia, muscle fasciculations, hypermetric, hypersensitivity; Confirmation Date: 9/3/2026; Horse Status: Affected And Alive; Vaccination Status: Undervaccinated;

Comments: The ninth (9th) equine case of West Nile Virus in California in 2026 was confirmed in Sacramento County. On September 3, 2026, a 3-year-old undervaccinated Oldenburg mare in Sacramento County displaying neurologic signs was confirmed positive for West Nile Virus. The mare is alive and recovering.;

Number Confirmed: 1; 
Number Exposed: 3; 
Facility Type: Private Facility; 

Horse 1: 
Age: 11; Gender: Mare; Breed: Quarter Horse (QH); Usage: Roping; Onset of Clinical Signs: 8/25/2026; Clinical Signs: 1 week of anorexia and ADR which progressed to ataxia, down and fever; Confirmation Date: 9/3/2026; Horse Status: Recovering; Vaccination Status: Unvaccinated;

Number Confirmed: 1; 
Number Exposed: 20; 
Facility Type: Private Facility; 

Horse 1: 
Age: 1; Gender: Mare; Breed: Quarter Horse (QH); Usage: Farm/Ranch; Onset of Clinical Signs: 8/30/2026; Clinical Signs: Weakness Ataxia Anorexia Teeth Grinding Fever; Horse Status: Affected And Alive; Vaccination Status: Unvaccinated;

Number Confirmed: 1; 
Number Suspected: Unknown; 
Number Exposed: Unknown; 

Horse 1: 
Age: 6; Gender: Mare; Breed: Quarter Horse (QH); Onset of Clinical Signs: 8/25/2026; Clinical Signs: hyperesthesia, muscle fasciculations; Confirmation Date: 9/3/2026; Horse Status: Affected And Alive; Vaccination Status: Unvaccinated;