The State needs to pull the shutters down on the countryside in response to foot-and-mouth, the president of the Irish Farmers' Association has said.
Mr Tom Parlon said the news that two sheep had been confirmed as having foot-and-mouth was a "major body blow", but he believed it was a secondary outbreak to the case at nearby Meigh, in south Armagh, and could be contained.
"The fact that it has happened in an exclusion zone with very strict controls is a positive. The indications I get are that it has been found very quickly and caught at a very early stage and I think that in terms of confinement we are well placed to confine it to the exclusion zone," he said.
Mr Parlon said he understood about 300 farmers on the Cooley peninsula would have 40,000 sheep slaughtered in the coming days. "It's going to devastate the Cooley area and I don't think it will be the same for a long time," he said.
He said he would be visiting farmers in the area to explain why they "were being sacrificed on the altar of the entire country".
The countryside, Mr Parlon said, should be considered to be "closed" in the wake of the announcement. "We have to pull the shutters down. When the pictures start going out this evening of Irish farmers seeing their animals destroyed, that will put the shockwaves out."
He said the IFA agreed with the Minister for Agriculture, Mr Walsh, that the restrictions could and should be limited to the exclusion zone around the outbreak. However, Mr Michael Berkery, the association's general secretary, said as the practice in Europe was now to base restrictions on the smallest administrative area, it was likely that all of Co Louth would be affected.
Mr Parlon said: "It is going to be crucial that we have access to the British market in the future because clearly we will be excluded from a number of other markets in the short term."
With hopes high that the virus could still be contained, Mr Parlon said the option of vaccination was still only an option for a "last stand" against the disease. "We have to focus totally on confining," he said.
Mr Pat O'Rourke, president of the Irish Creamery Milk Suppliers' Association, said he saw "the nearest thing I have ever seen to panic among the farmers in the area". Dairy farmers were already losing production, with milk being acidified and then poured into slurry tanks.
He said he was hopeful the European Commission would accept that only produce from within the exclusion zone would be affected by a ban. Dairy farmers in the area had already been affected by restrictions due to the outbreak in the North, but many more would now have to adapt.
The ICMSA would be meeting co-ops either later yesterday or today to discuss how quickly they could begin double pasteurising and fitting filters to milk tankers, he said.
The chairwoman of the Irish Tourist Industry Confederation called for a measured response to the crisis and warned of the dangers of overreaction.
Ms Eileen O'Mara Walsh said tourism was looking for "a more positive approach, while still keeping the restrictions".