Outbreaks | Equine Disease Communication Center

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.

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Equine Herpesvirus- Respiratory

Larimer County, CO

Outbreak Identifier: 7198

Alert ID: 4723

November 20, 2025

Confirmed Case(s) - Official Quarantine

Source: State Veterinarian

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

Horse 1:
Age: 13; Gender: Mare; Breed: Quarter Horse (QH); Usage: Barrel Racing; Onset of Clinical Signs: 11/18/2025; Clinical Signs: Febrile; Confirmation Date: 11/20/2025; Horse Status: Affected And Alive; Vaccination Status: Status Unknown;

Comments: EHV-1 positive but no neurological signs. This horse was exposed to EHV at the event in Waco, TX. The horse spiked a mild fever after returning home from the event. She is being closely monitored.;

For an up-to-date count of EHM cases tied to this outbreak, please visit HERE

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