Suspected cases of the virus, which can be carried by humans and is fatal to livestock, were reported in France, Belgium, Germany and Denmark.
And athletics became the latest sport to be placed under threat, with Brussels emerging as an alternative venue for the world cross country championships, if officials in Dublin decide it is too risky to host the event.
An announcement is expected from the International Amateur Athletics Federation (IAAF) today concerning the meeting, scheduled for the Leopardstown racecourse on March 24 and 25, with Spain, Portugal and Switzerland on stand-by to take over as hosts.
But an IAAF spokesman refused to rule out the possibility of cancelling the championships because of difficulties in reorganising transport and accommodation at such short notice.
"Brussels is the most likely alternative," he said. "But it would be very difficult to re-schedule the event, with the hotel situation particularly problematic."
A decision will also be taken today whether the Six Nations rugby union clash between France and Wales in Paris on March 17 can go ahead.
Last Saturday's fixture between Wales and Ireland in Cardiff was postponed over fears the 10,000 travelling Irish fans could spread the virus.
And the Irish Rugby Football Union (IRFU) will meet the government today to decide whether Ireland's match against England in Dublin on March 24 can take place.
But revised dates for postponed Six Nations matches have already angered England's top rugby union clubs, with several pointing out clashes with end-of-season play-offs and threatening not to release players.
During the last foot-and-mouth outbreak in 1967, the visiting All Blacks were denied the chance to complete a Grand Slam when the Irish refused them entry to the country for their final tour match.
And the players even had to burn their rugby shirts to be sure they did not bring the disease home with them.
In England, the horse racing programme was due to resume on Wednesday after a week-long suspension but events at Hereford, Chepstow, Carlisle and Towcester this week were cancelled because they fell within infected areas.
And Thursday's meeting at Wincanton was also called off because staff could not implement expensive disinfectant precautions in time.
"We intend to resume racing on Wednesday and will be looking at the options for where racing can take place," Jockey Club spokesman John Maxse said.
Organisers of the showcase Cheltenham Festival, set to begin on March 13, were optimistic yesterday they could stage the three-day event after a suspected case of the disease on a farm five miles (eight kilometres) away had still not been confirmed.
But a two-week ban in France on all horse racing and show jumping made it almost certain the French would follow the Irish in pulling out of the National Hunt event after fears the movement of horses could spread the disease.
"It is unlikely that our horses will be able to travel to Cheltenham," France Galop chief Louis Romanet said.
The loss of the Irish last week was a major blow to the festival, with three of last year's winners hailing from the Emerald Isle, but any French pull-out would put the event's viability in doubt.
Punters did receive a boost on Monday when bookmakers William Hill and Ladbrokes promised to refund stakes for ante-post bets on horses withdrawn from Cheltenham at the five-day declaration stage.
But an investigation into a suspected outbreak near Britain's biggest horse training centre at Lambourn could put the final nail in Cheltenham's coffin.
"We have to be sensible. If a major training centre like Lambourn was affected we would have to take a view as to whether the meeting was sustainable," Claisse said.
The town is set to lose an estimated 14 million pounds ($20.57 million) in revenue if the festival has to be cancelled. Last time the foot-and-mouth disease struck Britain in 1967 horse racing was halted for six weeks.
Reuters
