Disease Alerts

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

Horse 1: 
Age: 14; Gender: Mare; Breed: Thoroughbred (TB); Onset of Clinical Signs: 3/31/2026; Clinical Signs: This mare was found down in the field on Mar 31. She was assisted into the barn and then into isolation where she became recumbent with urinary incontinence. Her condition worsened and she was euthanized April 1. Blood and nasal swab samples were positive for EHV-1 by PCR.; Horse Status: Euthanized; 

Comments: The facility owner, working with their veterinarian, has instituted voluntary animal movement restrictions and biosecurity protocols. To see past and present EHV-1 neurologic (EHM) cases in Ontario go to: https://www.oahn.ca/resources/ontario-equine-disease-alerts/ and enter the disease surveillance portal;

Number Confirmed: 1; 
Facility Type: Private Facility; 

Horse 1: 
Age: 3; Gender: Gelding; Breed: Appaloosa; Usage: Horse Show; Onset of Clinical Signs: 2/12/2026; Clinical Signs: Mild nasal discharge 3 weeks ago accompanied by fever. Clinical signs resolved within 10 days. Guttural pouch lavage revealed continued abscesses in guttural pouches with some purulent discharge.; Confirmation Date: 3/25/2026; Horse Status: Quarantined; Vaccination Status: Unvaccinated;

Comments: Horse is under voluntary quarantine and management of the case, including guttural pouch flushes has been instituted.;

Number Confirmed: 1; 
Number Suspected: 1; 
Number Exposed: 40; 
Number Euthanized: 1; 
Facility Type: Boarding Facility; 
Comments: A veterinarian contacted my office to report a geriatric horse with neurological signs at a 40+ horse boarding facility. There are multiple owners and multiple veterinarians have patients there. This horse was euthanized and sent for cremation so no testing was conducted. She then reported a second horse with milder signs. No other horses at the farm are clinically affected. Both affected horses shared the same paddock but there are multiple paddocks. Horses otherwise of sharing a paddock have limited access to each other. The second horse was tested for EHV-1 by PCR and was confirmed to be positive. The farm owner is not aware of any horses recently leaving or coming to the farm, but by her admission, she may not have known if there was any movement of horses. She said most of the horses there have been there for years and don't leave the premises. Upon receiving lab confirmation a state quarantine was issued. The horse that was tested had mild neurological signs and those signs resolved with supportive treatment.;

Number Confirmed: 2; 
Number Suspected: 1; 
Number Exposed: 4; 
Facility Type: Private Facility; 

Horse 1: 
Onset of Clinical Signs: 3/23/2026; Clinical Signs: fever, cough, nasal discharge; Confirmation Date: 3/31/2026; Horse Status: Quarantined; Vaccination Status: Status Unknown;

Number Confirmed: 1; 
Number Suspected: 2; 
Number Exposed: 40; 
Facility Type: Training Facility;

Number Confirmed: 3; 
Number Suspected: 1; 
Number Exposed: 3; 

Horse 1: 
Age: 15; Gender: Mare; Breed: Paint; Onset of Clinical Signs: 1/10/2026; Clinical Signs: Fever, nasal discharge; Confirmation Date: 3/26/2026; Horse Status: Recovered; Vaccination Status: Unvaccinated;

Comments: This is the third confirmed case from the premises. The two prior cases were reported under alert 4731 and 4847.; 
Previous Alerts: 4847, 4731

Number Confirmed: 1; 
Number Suspected: Unknown; 
Number Exposed: Unknown; 
Facility Type: Boarding Facility;

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

Horse 1: 
Age: 15; Gender: Mare; Breed: Quarter Horse (QH); Usage: Rescue; Onset of Clinical Signs: 3/6/2026; Clinical Signs: Bilateral nasal discharge. Exposed to horses with strangles at previous premises; Confirmation Date: 3/23/2026; Horse Status: Affected And Alive; Vaccination Status: Unvaccinated;

Comments: Horse came from a local rescue that has a long history of transporting equines with strangles and other respiratory diseases.;

Number Confirmed: 1; 
Number Exposed: Unknown; 
Facility Type: Private Facility; 
Comments: Purchased at Billings horse sale. Under vet care. Recovering;

Number Confirmed: 10; 
Number Exposed: 25; 
Number Euthanized: 1; 
Facility Type: Private Facility; 
Comments: Quarantine was released on March 21.; 
Previous Alerts: 4905, 4904