Preliminary results from a suspected outbreak of the disease in Co Louth will be available this morning from a laboratory in London.
While the Department of Agriculture said it was treating the case as it had others in Carlow and Louth in the past three weeks, activity around the farm in Jenkinstown, Co Louth, would suggest otherwise.
The movement of all animals in Co Louth has been banned and extra gardai have been brought into the area to patrol an enlarged exclusion zone around the farm.
The drama began on Tuesday night when veterinary inspectors from the Department visited the farm, which is in the 10kilometre surveillance area put in place after the case in Meigh, Co Armagh, was identified on February 28th.
A number of sheep in the 150strong flock showed signs of illness and the officials immediately began to slaughter most of them. Tissue and blood samples were not ready in time to catch the last flights to London and it was early yesterday morning before they arrived there.
The Minister for Agriculture, Mr Walsh, who had met the task force for its daily briefing in Agriculture House, ordered a major readjustment to the control zone and the surveillance one surrounding it.
A Department spokesman said last night that one of the matters under investigation was possible nitrogen poisoning as urea had been spread on the farm in recent weeks.
However, not all the animals exposed to the grazing area showed symptoms of illness. In most outbreaks of foot-and-mouth in Britain, only a limited number of sheep in flocks showed symptoms.
Department officials do not believe the animals on the Jenkinstown farm have had contact with animals from Northern Ireland and have ruled out any possibility of airborne spread from Meigh or Britain.
Ironically, the suspect case in Louth, which is only a short distance from the island's only case of the disease in Meigh, came as authorities in the North announced "an adjustment" on restrictions placed around that farm.
The new guidelines will mean the three-kilometre restricted zone around the Co Armagh farm will become part of a wider 10-kilometre surveillance zone.
While in the restricted zone all movement of animals is banned, in the surveillance zone animals can be transported with a valid permit and in accordance with strict guidelines. A review of the surveillance zone is due on April 6th.
Meanwhile, the North's Livestock Auctioneers' Association has increased its reward for information about 60 missing sheep in Co Armagh to £4,000 sterling. The sheep are believed to have been imported as part of a larger consignment from a market in Cumbria, together with the 21 sheep at the source of the Meigh outbreak.
The livestock haulier who delivered the sheep from the Cumbrian market claimed yesterday that all the animals carried in his lorry had been accounted for, however. He told the BBC that while he had a permit for 291 sheep he only transported 270, all of which were dropped off in Meigh on the day in question.
As the number of confirmed cases in Britain soared to 430, the EU ordered a ban on the export of meat and meat products from the Netherlands, where there has been two confirmed cases. The EU's Standing Veterinary Committee also recommended an easing of restrictions on French exports.
From an Irish point of view, the most threatening of the outbreaks in Britain are in Anglesey, where another case of the disease was confirmed yesterday, bringing to 12 the number of infected farms there. There are a total of 30 confirmed cases in Wales and 15 more suspected cases.