Authorities Monitoring EHV-1 Cases in Canada

Two Canadian Standardbred horses have tested positive for equine herpesvirus-1 (EHV-1), according to the Ontario Racing Commission's (ORC) manager of veterinary services.

On May 21, Adam Chambers, BVMS, told that two horses have tested positive for the virus, one of which has been euthanized. The euthanized horse was previously stabled at the Campbellville Training Centre, a harness racing training facility located in Campbellville, Ontario, before falling ill, but had recently left the facility.

On May 17, the ORC issued a notice to the industry stating that "horses stabled at the Campbellville Training Centre from April 29, 2013, are ineligible to race in Ontario until further notice."

On May 20, the commission issued another industry notice extending the EHV-1 restrictions: "This order has now been extended to include horses stabled or were stabled from April 29, 2013, at a private stable known as 'Les Cedres.' The stable is located near the town of Les Cedres, Québec, which is approximately 25 kilometers (about 15.5 miles) from the Ontario-Québec border, off the Autoroute 20."

In the May 20 notice, the ORC noted that "this decisive measure is due to the infectious nature of this virus." Also in the notice, Chambers said that EHV-1 outbreaks have a significant risk of mortality: “Anything that touches an infected horse or carries secretions or manure from sick horses has the potential to transfer pathogens to other horses.”

Chambers cautioned that racehorses showing signs consistent with EHV-1 infection should be examined by an ORC-licensed veterinarian.

“Clinical signs of EHV-1 infection include but are not limited to fever, cough, nasal discharge, and neurological abnormalities," he said in the notice. "The incubation period of EHV-1 infection has been reported to be as long as 14 days.”

Any suspected cases should be reported to Chambers or Bruce Duncan, DVM, the ORC's supervisor of commission Standardbred veterinarians, the notice said.

Chambers reminded participants to use caution and take appropriate biosecurity measures: “As a standard practice, racetrack management needs to maintain aggressive disinfectant programs in ship-in barn areas. Further, trainers should continue checking their horse’s temperature frequently (at least once per day) and prior to shipping into an Ontario racetrack.” will continue to provide information as it becomes available.

About the Author

Erica Larson, News Editor

Erica Larson, news editor, holds a degree in journalism with an external specialty in equine science from Michigan State University in East Lansing. A Massachusetts native, she grew up in the saddle and has dabbled in a variety of disciplines including foxhunting, saddle seat, and mounted games. Currently, Erica competes in eventing with her OTTB, Dorado.

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