Woodbine racetrack’s Barn No. 1 was put under quarantine by Woodbine Entertainment Group Tuesday morning on the advice of veterinarians after a horse was euthanized on Monday after showing signs of fever and neurological problems.

The deceased horse, an unraced 2-year-old filly trained by Tom O’Keefe, was shipped to the Ontario Veterinary College in Guelph for tests. Another horse in the same barn was also sent to the OVC suffering from similar symptoms.

Those symptoms could suggest any number of diseases, including the equine herpes virus (EHV-1), a common, airborne viral infection which can cause respiratory disease, abortion, death in newborn foals and a neurological form of herpes.

The disease is contagious and can be passed around other horses through close proximity, secretions or manure. It also has a high fatality rate.

Cases of EHV-1 recently briefly shut down Finger Lakes and Vernon Downs tracks in upper New York State. On May 17, the Campbellville Training Centre for standardbreds near Mohawk Raceway was under quarantine for 21 days when two horses were found to have EHV-1.

However, Dr. Adam Chambers, manager of veterinary services for the Ontario Racing Commission, said early test results obtained Tuesday afternoon on the deceased horse gave him “nothing to hang his hat on” as far as the cause.

“Obviously there is an infectious agent causing this problem,” said Chambers. “I am not ready to say it’s EHV-1 but I have suggested (Woodbine) and horsemen take the necessary precautions.”

Steve Koch, vice-president of thoroughbred racing for WEG, said it was agreed that a quarantine of Barn No. 1, which includes trainers Paul Attard and John Ross, was in order until “we know what we are dealing with.”

If the disease is found to be EHV-1, the horses in Barn No. 1 will not be allowed to train during regular training hours as long as the quarantine is in place. They could, depending on the spread of it, leave the barn for exercise after the rest of the track has trained.

More test results were expected by Wednesday morning.