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.



Strangles
Grey County, ON
Outbreak Identifier: 5548
Alert ID: 2945
March 30, 2023
Confirmed Case(s) - Voluntary Quarantine

Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA)

Number Confirmed: 1; 
Number Exposed: 24; 
Age: 8; Gender: Gelding; Breed: Thoroughbred (TB); 
Clinical Signs: The gelding was examined on March 23, 2023 for the development of a fever and submandibular draining tract. The exudate was positive for S. equi by PCR. The horse has lived on the property for almost a year. There have been no new horses recently and no other horses are showing clinical signs.; Confirmation Date: 3/27/2023; Horse Status: Recovering; 
Comments: The facility owners are working with the farm veterinarian to implement voluntary movement restrictions and biosecurity measures. For more information go to: https://www.equinediseasecc.org/strangles

Strangles
Lincoln County, WA
Outbreak Identifier: 5547
Alert ID: 2944
March 28, 2023
Confirmed Case(s) - Voluntary Quarantine

State vet office.

Number Confirmed:
Number Exposed:
Facility Type: Private Facility 
Comments: A horse in Lincoln County has tested positive for Strangles. The horse is under veterinary care and the owner is taking biosecurity precautions and under self quarantine. For more information go to: https://www.equinediseasecc.org/strangles

Equine Herpesvirus- Neurologic
Los Angeles County, CA
Outbreak Identifier: 5537
Alert ID: 2943
March 28, 2023
Quarantine Released

California Department of Food and Agriculture

Number Confirmed:
Number Exposed: 61 
Facility Type: Private Facility 
Comments: No additional cases were confirmed during the quarantine monitoring period. The quarantine has been released.
Previous Alerts: 2932

Equine Infectious Anemia
Fresno County, CA
Outbreak Identifier: 5546
Alert ID: 2942
March 24, 2023
Confirmed Case(s) - Official Quarantine

California Department of Food and Agriculture

Number Confirmed: 1; 
Number Exposed: 6; 
Facility Type: Private Facility; 
Age: 21; Gender: Mare; Breed: Mule; Usage: Retired; 
Clinical Signs: Asymptomatic, tested prior to interstate movement.; Confirmation Date: 3/21/2023; 
Comments: A 21-year-old mare mule in Fresno County has been confirmed positive for Equine Infectious Anemia (EIA). The mule has been quarantined on her home premises with 6 additional potentially exposed equids, 1 additional mule and 5 horses, none of which have had show or travel history in the past six months. An epidemiological investigation is ongoing but transmission is suspected to be via natural vectors (eg, biting flies). For more information and updates, go to:https://www.cdfa.ca.gov/ahfss/Animal_Health/EquineInfectiousAnemia.html. For more information about EIA go to: https://www.equinediseasecc.org/equine-infectious-anemia

Strangles
Lanark County, ON
Outbreak Identifier: 5545
Alert ID: 2941
March 22, 2023
Confirmed Case(s) - Voluntary Quarantine

Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA)

Number Confirmed:
Number Exposed: Unknown 
Facility Type: Boarding Facility 
Age: 13; Gender: Mare; Breed: Quarter Horse (QH); Onset of Clinical Signs: 3/16/2023
Clinical Signs: On March 16, the mare developed a fever and a unilateral, foul-smelling nasal discharge which was PCR positive for S. equi. Since a foul smell is not typically consistent with S. equi infection alone, further diagnostic evaluations will occur. There have been no other horses with clinical signs of Strangles on the farm and no recent horse movement. The mare has been on the property for over a year.; Confirmation Date: 3/21/2023 
Comments: The facility owner is working with the attending veterinarian regarding biosecurity and movement restrictions. For more information go to: https://www.equinediseasecc.org/strangles

Equine Herpesvirus- Neurologic
Riverside County, CA
Outbreak Identifier: 5541
Alert ID: 2940
March 22, 2023
Outbreak Update

California Department of Food and Agriculture

Number Confirmed: 2; 
Number Exposed: 600; 
Age: 12; Gender: Mare; Breed: Argentinian Polo Horse; Usage: Polo; Onset of Clinical Signs: 3/19/2023
Clinical Signs: mild neurologic; Confirmation Date: 3/21/2023; Horse Status: Affected And Alive 
Comments: A 12-year-old Argentinian polo horse mare displaying mild neurological signs has been confirmed positive for EHM secondary to EHV-1 (non-neuropathogenic strain). The mare was immediately isolated at the onset of clinical signs and is currently alive and under veterinary supervision. Out of an abundance of caution following the confirmation of ongoing viral presence on the premises, the entire facility with 600 horses onsite, previously under voluntary quarantine, has been placed under mandatory quarantine with twice daily temperature monitoring and enhanced biosecurity measures in place. All polo activities in the surrounding area remain voluntarily postponed until further notice. CDFA was onsite, and will continue to closely and actively monitor the situation. 
Previous Alerts: 2936

Equine Herpesvirus- Neurologic
Pueblo County, CO
Outbreak Identifier: 5544
Alert ID: 2939
March 21, 2023
Confirmed Case(s) - Official Quarantine

State Veterinarian's Office

Number Confirmed:
Number Suspected:
Number Exposed: 20 
Facility Type: Boarding Facility 
Age: 10; Gender: Gelding; Breed: Quarter Horse (QH); Usage: Horse Show; Onset of Clinical Signs: 3/13/2023
Confirmation Date: 3/17/2023; Horse Status: Quarantined; 
Age: 11; Gender: Gelding; Breed: Warmblood (WB); Usage: Pleasure Riding; Onset of Clinical Signs: 3/7/2023
Confirmation Date: 3/17/2023; Horse Status: Quarantined
Comments: For more information go to: https://www.equinediseasecc.org/equine-herpesvirus

Equine Herpesvirus- Neurologic
Pueblo County, CO
Outbreak Identifier: 5543
Alert ID: 2938
March 21, 2023
Confirmed Case(s) - Official Quarantine

State Veterinarian's Office

Number Confirmed:
Number Exposed: 25
Facility Type: Boarding Facility
Age: 23; Gender: Gelding; Breed: Quarter Horse (QH); Usage: Pleasure Riding; Onset of Clinical Signs: 3/14/2023
Confirmation Date: 3/20/2023; Horse Status: Quarantined
Comments: For more information go to go:https://www.equinediseasecc.org/equine-herpesvirus

Strangles
Wellington County, ON
Outbreak Identifier: 5542
Alert ID: 2937
March 20, 2023
Confirmed Case(s) - Voluntary Quarantine

Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA)

Number Confirmed: 1
Number Exposed: Unknown
Facility Type: Boarding Facility
Age: 4; Gender: Mare; Breed: Thoroughbred (TB); Onset of Clinical Signs: 3/12/2023
Clinical Signs: The affected mare was recently purchased, arriving on the property March 4. The mare came from a farm from which a horse was confirmed with Strangles March 13. The present mare developed a fever followed by nasal discharge and swollen submandibular lymph nodes and tested positive for S. equi by PCR. Confirmation Date: 3/17/2023; Horse Status: Recovering.
Comments: A horse at a boarding facility in Wellington County has tested positive for Strangles. She has been moved to a vacant barn on a nearby property. The remaining horses are being monitored for clinical signs of S. equi infection. The facility owner is working with the attending veterinarian regarding biosecurity and movement restrictions. For more information go to: https://equinediseasecc.org/strangles

Equine Herpesvirus- Neurologic
Riverside County, CA
Outbreak Identifier: 5541
Alert ID: 2936
March 16, 2023
Confirmed Case(s) - Official Quarantine

California Department of Food and Agriculture

Number Confirmed: 1
Number Exposed: 9
Facility Type: Event Center
Age: 17; Gender: Mare; Breed: Polo pony; Usage: Polo; Onset of Clinical Signs: 3/11/2023
Clinical Signs: Dragging pelvic limb 2 days prior to decreased appetite, ataxia, and reactivity on cervical spinal palpation, then found recumbent and unable to rise the following morning. Afebrile.; Horse Status: Euthanized; Vaccination Status: Status Unknown
Comments: A 17-year-old polo horse mare at a polo facility in Riverside County displaying nonspecific lameness followed by severe neurological signs on March 14th was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to Equine Herpesvirus-1 (EHV-1, non-neuropathogenic strain) on March 16th. The mare had not participated in any practices or matches over the past week, and was euthanized due to severity of clinical signs. Nine (9) horses housed with the index case were immediately isolated at an adjacent empty premises and subsequently quarantined with enhanced biosecurity measures implemented. CDFA is working with the attending veterinarian and polo club management to ensure all horses that have visited the polo facility in the past two weeks are monitored closely and owners adhere to biosecurity recommendations both at the polo facility and their home premises. Out of abundance of caution, all polo activities in the local area have been voluntarily postponed until further notice. CDFA will continue to closely and actively monitor the situation. For more information and updates, go to: https://www.cdfa.ca.gov/ahfss/Animal_Health/equine_herpes_virus.html