LONDON, United Kingdom | AFP | - British horse racing will not resume until next Wednesday at the earliest as authorities wait to find out the extent of the equine flu crisis that has brought the sport to a halt.
Four meetings were cancelled on Thursday after three animals tested positive for equine influenza despite having been vaccinated against the disease and Friday's meetings were also abandoned.
Grand National-winning trainer Donald McCain confirmed the horses came from his Cheshire stables.
The British Horseracing Authority (BHA) said it had been in contact with more than 50 trainers and vets to allow it to make an informed assessment of the risk of the disease spreading.
The BBC reported more than 100 stables were on lockdown, with hundreds of horses effectively under quarantine.
"The disease can take up to three days before symptoms are visible, meaning it will take until Sunday at the earliest before the BHA can gather all the information required," the BHA said.
"This precautionary approach is intended to ensure we put the health of the horse population and control of the virus first, and avoid any unnecessary risk that might come from returning to racing too quickly," it added.
Trainers Nicky Henderson and Paul Nicholls are among those affected by the shutdown.
"I'm estimating that there will be 1,500-plus taken overall today," Henderson told BBC Radio, referring to swab tests being carried out by vets.
Equine influenza is a highly infectious disease of horses with symptoms including high fever, coughing and nasal discharge.