Grand National winning horse trainer Donald McCain has confirmed the three horses to test positive for Equine Influenza are from his Cheshire yard.
The outbreak has forced the cancellation of all British racing on Thursday, after three horses tested positive for equine influenza, despite having been vaccinated against it.
It said the cancellation was 'a precaution' and humans are not at risk from the virus.
In a statement, McCain said his Bankhouse stables had had three confirmed cases.
“I have been aware of the recent news about Equine Influenza outbreaks in France and Ireland, and over the last couple of days, I have been concerned about the health status of a small number of horses in the yard.
This is a standard contingency in the event of an infectious disease affecting our horses. "It was essential that racing be stood down today and controls on movements of horses be put in place in order to attempt to control the spread of the disease, and the decision was taken swiftly last night that this course of action should be taken, once the extent of the issue was known.