The possibility of a foot-and-mouth disease outbreak has implications not just for farmers but for food processors and people working in the food industry, road hauliers, exporters and the economy in general. Indeed, it is hard to see what other disease could affect the whole economic fabric of the State so much, such is the contagious nature of the virus.
While foot-and-mouth disease has no implications for human health, the impact on our massive food industry, which is so dependent on exports, is almost incalculable. And coming on top of BSE and the many food scares of recent years, it will pose a further issue for consumer confidence in food, even if the disease itself has no effect on the food we eat.
Although the EU Health and Consumer Protection Commissioner, Mr David Byrne, says there is no case for a ban on Irish exports, the feeling in Brussels seems to be that if the disease is discovered here he will have no choice but to impose one. The blow might be softened, it is suggested, by allowing trade between Ireland and Britain to continue.
A ban on food exports would affect a huge chunk of the workforce and some of our biggest companies, which happen to be food companies, like Kerry Group, Dairygold, AIBP, Glanbia and Kepak.
There are 130,000 farmers in the State but 44,000 other people are employed directly in the food industry and 200,000 in the agrifood industry generally, so the spin-off implications for trading and employment are significant.
Few people still farming can remember the last outbreak here. Few vets - unless they have worked abroad in areas where the disease is endemic - would have seen such an exotic disease. So the measures which must be taken to ensure that if it is found, it does not spread, are all new to almost everyone involved. For example, the Department of Agriculture and Food is issuing guidelines for farmers about what disinfectants to be used in special straw mats across entrances to their properties - but will there be sufficient supplies to meet the demand?
We export just over £5 billion worth of food every year - around 80 per cent of what we produce - which is by far the highest level of exports of food production of any EU state.
In the "what if?" scenario - what if foot-and-mouth disease is confirmed in this State? - it's hard to see how the impact will not be very severe on industry and jobs, as well as on farmers.
Sporting events may have been the first to be cancelled. But as the Minister for Agriculture and Food, Mr Walsh, announced emergency measures to cope with the quickly changing situation yesterday, food processors and exporters were considering the implications for their industry.
"The public need to know what to do to prevent the spread of the disease," Mr Michael Duffy, chief executive of Bord Bia, warns. "It's important people understand the economic stakes here. The image of Ireland abroad as a good food island and the fact of our class A disease-free status has served us well in the past. In the current (BSE) situation, it makes a difficult environment more complicated," he says.
Mr Duffy, who has an overview of the food industry, says this is a very worrying time. "The food industry accounts for half the exports of Irish-owned companies. Nine out of 10 cattle, three-quarters of every gallon of milk produced, are exported. Our two biggest industries are heavily dependent on exports - they account for £3 billion of exports. The issue is the effect it would have on those two sectors.
"It's absolutely critical that everything is done and everybody associated with the food industry will take whatever steps are necessary and take them effectively and efficiently."
Issues such as the movement of cattle, sheep and pigs from farms to factories or abattoirs and the double pasteurisation of milk are among the industry's main concerns.
Mr John Smith, chief executive of the Irish Meat Association, says the meat factories will stick rigidly to whatever decisions the veterinary authorities and the Department make. Beef exports are worth £1.1 billion and sheepmeat £145 million. Pigmeat exports, which do not come within Mr Smith's remit, are worth £220 million.
Mr Noel Cawley, chief executive of the Irish Dairy Board, says the situation could become very serious if an outbreak of the disease is confirmed here. There are mechanisms for dealing with it but it would take a lot of handling, he says. "Some customers will raise questions and it will pose serious problems for the dairy industry. We will be able to deal with it but it won't be easy; there's no point in putting a gloss on it.
"The issue is how they [the processors] are going to collect milk. There are a lot of difficulties. And it will pose considerable problems at processing level and on export markets," he says.
If foot-and-mouth disease is confirmed here, there is little we can do other than slaughter affected animals, control the movement of all animals - and even people - and put a major disinfection programme in place. But few Irish vets have seen the disease, unless they have worked in Asia, the Middle East or perhaps South Africa.
Prof Joe Quinn of UCD's veterinary college is familiar with the disease, which he says has seven major sero-types, distributed in different parts of the world, and 60 subzero-types. There's no point in vaccinating, even if the EU allowed it, which it does not. He says that if there was an overwhelming outbreak, vaccination might have to be considered, but he "would not support vaccination".
He says the type of foot-and-mouth in Britain is highly virulent and if a case is confirmed here the disease could have been on the island for some time.
A worried Mr Tom Parlon, leader of the Irish Farmers' Association, who returned to Ireland via Belfast on Tuesday night, says controls at the Border were exceedingly strict. The Republic of Ireland is what's called a "white listed" country and has access for its food products to every market in the world. "If we were to have one outbreak we would lose our `white listed' status and that would have implications for us in the future. It's going to be a factor in a decision on who you would deal with."
He concedes that while banning movement of all cattle except to abattoirs and meat factories will prevent unnecessary animal contact, milk collection, where tankers have to enter farms several times a week, poses a real contact problem. "We need all farmers to take their own precautions," he warns.