The Equine Disease Communication Centre (EDCC) has issued an update regarding the Strangles outbreak at an Ontario Standardbred training facility located in Middlesex County.
The Strangles outbreak at this Standardbred training facility was first confirmed on Dec. 9, 2025. As of Jan. 2, 2026, there have been seven confirmed and four suspected cases of Strangles at the facility. The first group of affected horses (three confirmed, two suspected) have recovered and are being tested at one isolation facility. The second group of affected horses (four confirmed and two suspected) were voluntarily moved to a second isolation facility on Jan. 2, 2026. All affected horses were housed in Barn 1 at the facility.
The timeline of events follows.
On Dec. 8, 2025, all foot traffic ceased between the affected quadrant and remainder of Barn 1 with physical barriers in place. The 14- day voluntary animal movement restrictions began with twice daily temperature monitoring of the horses and biosecurity measures used. During this time, Barns 2 and 3 at the facility carried on business as usual and were permitted to race as they had had no evidence of disease and no direct or indirect contact with the Strangles cases in Barn 1. These racehorses posed no increased risk to the industry.
Between Dec. 16 and 20, two young horses developed clinical signs of respiratory disease in Barn 1. Both tested negative for Strangles (S. equi) but positive for the same respiratory virus. Similar (and suspected) upper respiratory viral infections had been circulating within the Standardbred yearling population, according to local racehorse veterinarians. This circulating respiratory virus was an unexpected challenge.
On Dec. 23, the 14-day voluntary movement restrictions ended as no further Strangles cases could be confirmed. The Alcohol and Gaming Commission of Ontario (AGCO), which regulates the industry, permitted horses to race. However, due to weather cancellations, no horses from Barn 1 raced between Dec. 23 and Dec. 29. During the week of Dec. 22-27, more young horses in the same shedrow of Barn 1 continued to have fevers, nasal discharge and lymph node swelling which were initially thought to be due to the circulating virus. However, these lymph nodes began to abscess and drain and Strangles (S. equi) was confirmed on Dec. 29, including in a yearling that previously tested negative. The trainers in Barn 1 promptly restricted animal movement again. Trainers in Barn 2 also restricted animal movement as a precaution as there had been some common staff managing horses in Barn 1 and 2 during this week. Barn 3 at the facility has remained independent of the other two barns, has biosecurity protocols in place and has no indirect or direct contact with the Strangles cases.
On Dec. 29, a four-year-old racehorse in Barn 1, with a different trainer, developed a single swollen lymph node (no fever, no nasal discharge).
On Jan. 2, all confirmed and suspected Strangles cases from Barn 1 were isolated at an off-site facility. Trainers in Barn 1 are continuing to voluntarily restrict movement of their horses and monitor them for signs of disease. The attending veterinarians will continue to manage this challenging outbreak with the cooperation of trainers at the facility. OMAFA will continue to provide advice as requested while the AGCO is the body that determines the eligibility of horses to race.
(With files from EDCC; Horse pictured does not have strangles)