All British horse racing on Thursday has been cancelled because of an outbreak of equine flu.
The decision by the British Horseracing Authority (BHA) comes after three vaccinated horses in an active yard tested positive for the disease.
Horses from the infected yard raced on Wednesday, potentially exposing a significant number of horses.
Four British meetings were scheduled for Thursday – Huntingdon, Doncaster, Ffos Las and Chelmsford.
Horses that have contracted equine flu can develop a high fever, coughing, nasal discharge and sometimes swelling of the lymph nodes. The incubation period is usually days but recovery can take weeks, or even months.
“The fact that the cases have been identified in vaccinated horses presents a cause for significant concern over welfare and the potential spread of the disease and the action to cancel racing has been viewed as necessary in order to restrict, as far as possible, the risk of further spread of the disease,” the BHA said in a statement.
“The BHA has worked quickly to identify which yards could have potentially been exposed today and identify the further actions required.
“The BHA is presently communicating with yards potentially exposed to ensure appropriate quarantine and biosecurity measures are put in place and horse movements restricted to avoid possible further spread of the disease.
“The full extent of potential exposure is unknown and we are working quickly to understand as much as we can to assist our decision making.”
Since the start of 2019, there have been seven outbreaks of equine flu – in Essex, Cheshire, Derbyshire, Lincolnshire, Yorkshire and Suffolk.
The two cases in Suffolk involved thoroughbreds – one centred on eight vaccinated two-year-old horses and the other was six unvaccinated animals.