July 25, 2021
Equine Herpesvirus- Neurologic
Sonoma County, CA
Alert ID: 2139
Status: Confirmed Case(s) - Official Quarantine
Source: California Department of Food and Agriculture
Number Confirmed: 5;
Number Suspected: 4;
Number Exposed: 19
Facility Type: Showgrounds;
Horse #1: Age: 6; Gender: Mare; Breed: Warmblood (WB); Onset of Clinical Signs: 7/23/2021;
Clinical Signs: Hind-end Weakness, Limb edema, Nystagmus, Recumbency; Confirmation Date: 7/24/2021; Horse Status: Euthanized; Vaccination Status: Vaccinated;
Horse #2: Age: 15; Gender: Gelding; Breed: Warmblood (WB); Onset of Clinical Signs: 7/22/2021;
Clinical Signs: Ataxia, Cranial Nerve Deficit, Fever, Neurologic Signs, Urine Dribbling; Confirmation Date: 7/23/2021; Horse Status: Affected And Alive; Vaccination Status: Status Unknow
Notes: A 6-year-old Warmblood mare displaying neurological signs has been confirmed positive for EHM secondary to EHV-1. She attended a show in Sonoma County from 7/19-7/24 but did not compete, and event management has notified all participants to monitor temperatures twice daily and report any fevers or neurologic signs to their veterinarians and CDFA, as well as isolate all horses returning from shows at their home premises for at least 7 days. CDFA was onsite, and 19 exposed horses from the index mare’s barn were removed from the show facility and have been isolated and quarantined at the home premises in Sacramento County with the remaining 18 horses at the home premises with twice daily temperature monitoring and enhanced biosecurity measures. Six (6) horses from the home premises displaying fever and/or limb edema have also tested positive for EHV-1. A 15-year-old Warmblood gelding at the home premises that was febrile and tested positive for EHV-1 began displaying neurological signs, ataxia, urine dribbling, and cranial nerve deficits and was moved to isolation under quarantine at a veterinary hospital for care. CDFA continues to actively monitor the situation.
