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Disease Alerts

Updates on current disease outbreaks are listed here as they occur and will include the date listed, disease name, location and current status. Specific premises will not be named but the general location by town, county and state will be listed. When locations, events or horses are at risk they will be listed. Updates will be posted as they are received.



West Nile Virus
Placer County, CA
Outbreak Identifier: 6326
Alert ID: 3804
July 26, 2024
Confirmed Case(s) - No Quarantine

California Department of Food and Agriculture

Number Confirmed: 1; 
Number Exposed: Unknown; 

Horse 1: 
Age: 6; Gender: Stallion; Breed: Andalusian Cross; Onset of Clinical Signs: 7/17/2024; Clinical Signs: ataxia, muscle fasciculations in muzzle, grinding teeth, decreased appetite; Confirmation Date: 7/25/2024; Horse Status: Affected And Alive; Vaccination Status: Status Unknown;

Comments: The first (1st) case of West Nile Virus in California in 2024 was confirmed in Placer County. On July 25, 2024, a 6-year-old Andalusian cross stallion in Placer County with an unknown vaccine history displaying neurologic signs was confirmed positive for West Nile Virus. The stallion is alive and recovering.;
West Nile Virus
Harper County, OK
Outbreak Identifier: 6324
Alert ID: 3802
July 26, 2024
Confirmed Case(s) - No Quarantine

State Veterinarian

Number Confirmed: 1; 
Facility Type: Farm; 

Horse 1: 
Age: 3; Gender: Gelding; Breed: Quarter Horse (QH); Onset of Clinical Signs: 7/18/2024; Clinical Signs: Incoordination/ataxia in all four limbs.; Confirmation Date: 7/25/2024; Horse Status: Recovering; Vaccination Status: Unvaccinated;
West Nile Virus
Frederick County, MD
Outbreak Identifier: 6322
Alert ID: 3800
July 25, 2024
Confirmed Case(s) - No Quarantine

Maryland Department of Agriculture

Number Confirmed: 1; 

Horse 1: 
Horse Status: Recovered; Vaccination Status: Vaccinated;
West Nile Virus
Nye County, NV
Outbreak Identifier: 6320
Alert ID: 3798
July 24, 2024
Confirmed Case(s) - No Quarantine

The Nevada Department of Agriculture

Number Confirmed: 1; 
Number Euthanized: 1;
West Nile Virus
Clark County, NV
Outbreak Identifier: 6319
Alert ID: 3797
July 24, 2024
Confirmed Case(s) - No Quarantine

The Nevada Department of Agriculture

Number Confirmed: 1; 
Number Euthanized: 1;
West Nile Virus
Région du Saguenay, QC
Outbreak Identifier: 6309
Alert ID: 3787
July 16, 2024
Investigation Initiated

MAPAQ

Number Exposed: Unknown; 
Facility Type: Stable; 

Horse 1: 
Age: 20; Gender: Mare; Breed: Quarter Horse (QH); Onset of Clinical Signs: 6/26/2024; Clinical Signs: Altered mental state, seemed sedated, facial nerve damage on right and left, head tilted intermittently to the left, very slight proprioceptive ataxia of the thoracic limbs especially. Delayed grasping of food and mastication. No fever.; Confirmation Date: 7/12/2024; Horse Status: Recovering; Vaccination Status: Undervaccinated;

Comments: Possible case of WNV upon CFIA definition case with compatible clinical signs and positive ELISA IgG. IgM is negative.