The autumn migration will probably start any time now, and it's rather like coming up onto your toes and getting ready to run, if you know what I mean

Barely has the prospect of a foot and mouth outbreak in Northern Ireland dwindled than the next threat looms.

After enduring his most fraught month since the major outbreak of 2001, Chief Veterinary Officer Bert Houston is now poised to deal with the next animal disease threat, as wild birds begin to gather for the autumn migrations.

"Avian influenza is still out there - it's still a major threat," he warned.

"The autumn migration will probably start any time now, and it's rather like coming up onto your toes and getting ready to run, if you know what I mean."

Contingency plans to deal with the virulent H5N1 strain of bird flu have been drawn up by the Department of Agriculture and Rural Development (DARD) and are tested regularly, including a number of test culls of chickens.

"It's just a matter of building up the knowledge across the countryside, both in the farming industry and within our own staff in preparation for all of this, making sure that everyone knows what avian influenza is, that it's there and will increase slightly as a result of the autumn migration," said Dr Houston.

"In some ways Northern Ireland is fortunate in that most of the flightways are coming up from eastern Europe and will reach others before they reach us, so we have an early warning system in place."

Although Northern Ireland has escaped relatively unscathed - touch wood - from the latest foot and mouth scare, just the suggestion a few weeks ago that we could be about to revisit the dark days of 2001 were enough to inspire panic.

In 2001, Dr Houston witnessed the harrowing effects of a true foot and mouth outbreak - although we still didn't have the worst of it - as trade was suspended and Ulster's countryside came to a standstill. It's estimated the 2001 outbreak cost around £3.1m.

"I was deputy chief veterinary officer then, and it was tough," he said.

"My role was mainly animal welfare, and it was difficult to tell farmers that they couldn't move their animals when they desperately needed to move their animals.

"Northern Ireland did handle it well and we came out of it well. Certainly the lessons learned in 2001 were very very valuable - we were instantly at the ports, we instantly had all our material there, we had all our planning, we knew what we were going to do."

At 7.30pm on Friday, August 3, Defra announced that a suspected case of foot and mouth had been found and DARD's staff swung into action.

Dr Houston said: "I asked them to make sure that the minister's wishes were adhered to and no animals landed, and so therefore they were contacting their colleagues on the Scottish side to make sure there were no animals on the ferry that was due to dock at eight o'clock.

"If there had been, we would have had to make arrangements to send them back - they were not coming in. We had created the island of Ireland as an epidemiological unit and it was important that we try to maintain that. There would be daily telephone calls with our colleagues in the Republic to get their take on the current situation and find out whether we were in line with them.

"Within 48 hours we had mobilised over 40 vets to go out and trace down all the animals which had been imported since July 1 and to confirm that those animals were free from clinical signs.

"Also on that evening we had 53 portal inspectors and they played a vital role on the first evening because no animals were getting in from Britain after the confirmation at 7.30pm."

Efforts to distance Northern Ireland from the Surrey outbreak paid off, with the European Commission agreeing to exempt the region from the UK export ban, a decision ratified by the chief vets from the EU member states. Dr Houston said his counterparts in Defra and the Department of Agriculture and Food in the Republic played a major role in persuading member states to differentiate Northern Ireland from the rest of the UK.

While the message took some time to filter through to some non-EU countries, Dr Houston said DARD and the ministers have done well to get exports to the US moving again so quickly, putting the success down to the swift, decisive action taken by the Minister, Michelle Gildernew.

"She was very well supported by her Executive colleagues and especially the First Minister and Deputy First Minister who very ably supported her in terms of trying to keep trade flowing to Northern Ireland."

Veterinary science runs in the Houston family - the chief vet says his sister, brother-in-law and nephew have all followed the same profession, and so did his father, who practised in the Ballymoney area.

He himself spent six years in general practice, mostly mixed animals in the Ballymena and Ballymoney areas, but also some small animal work in Belfast and Calgary in Canada.

He joined the Department in 1983, intending to work there as a temporary break from the rigours of general practice - and stayed.

"I've enjoyed all my time in the department, even times when it was tough like the foot and mouth outbreak," he said.

As for the challenges to come, Dr Houston identifies avian influenza and blue tongue as the major diseases approaching our shores. DARD has already drawn up contingency plans for avian influenza and is starting on the blue tongue plan.

"We've also been looking at other diseases such as swine fever and rabies. Having said that, there is a core of work which, once done, you would replicate in any scenario so a lot of the work we've done in this particular outbreak will be very similar to the reaction taken in other outbreaks.

"There will be subtle differences in terms of trade and other decisions to be taken but the process will be similar."

Dr Houston insists there is a considerable challenge ahead in meeting the threat of blue tongue which moved north into northern European cattle herds for the first time last year. The disease is transmitted by biting insects.

"Just at this minute we've had outbreaks of blue tongue in western Germany and in Belgium, so it has moved slightly further west," he said.

"Blue tongue is an interesting one because its vector is an insect, which means that although the disease is infectious, it's not contagious, so they don't pass it from animal to animal - it has to go through the insect vector and that lends an entirely different perspective.

"We're used to 3km and 10km protection and surveillance zones. In blue tongue they become vastly greater- they become 20km and 100km or 150km. You start to have a huge control area but, having said that, blue tongue has no effect on products in terms of trade - live animals, yes, products no."

Dr Houston said he was impressed with how Defra produced a daily foot and mouth situation report to keep people briefed on progress.

"There will certainly be lessons to be learned in this outbreak. We're starting a process now of how we would gather information about the things we did well and the things we did not so well. It's not just ourselves - it's very important to look across at how Defra managed things."