Ministry for Primary Industries chief veterinary officer Dr Mary van Andel said a specialised task force has been established in case of an outbreak and it is busy planning for a range of scenarios.
"What our workforce requirements would be, what type of planning we would need, what would our operational guidelines in the field would look like, what type of tactics we would use, what would we need to be doing for animal welfare, what would we need to be doing for farmer welfare?"
She said due to the scale of the potential problem, MPI was working closely with other government agencies, industry partners and stakeholders.
If an outbreak was confirmed, a government-wide response would kick in and any infected animals would be killed, she said.
There were telltale signs for farmers to watch out for, she said.
"Animals that have foot and mouth disease will initially show fever, they'll be drooling with lots of saliva coming out the mouth and they won't be wanting to move around, so they're lame and drooling and look very, very miserable indeed.
"The reason that these are the clinical signs that you'll see, is that foot-and-mouth disease causes fluid-filled blisters that have formed on the lips, the tongue, the palate and the coronary bands of the hoof, so that's the little bit just above the hoof where the hoof joins the leg to the skin of the leg.
"And they also happen on the teats of infected animals, so these blisters, after a couple of days, will burst and leave an ulcer and that can take 10 days or so to start to heal up."
She said if a farmer contacted MPI concerned their stock might be infected, it would be examined and tested within a matter of hours.
If a case was confirmed, contact tracing would begin immediately and livestock movements would be halted, she said.
"No animals would be allowed to move if an infection is confirmed in a particular place, and also there would be measures in place about moving animal products," van Andel said.
"If an infection is confirmed at a farm, then people would need to disinfect on and off that place so that they don't move disease around.
"One of the other huge impacts that would happen would be that our trading partners would no longer accept our products if we had foot-and-mouth disease in New Zealand, so that would be a huge problem and would be why this disease would need to be eradicated extremely quickly so that we could return to trading, which is what our primary sector relies on."
New Zealand had exclusive access to a vaccine bank of the most common strains of foot and mouth, but as the vaccine needed to match the circulating strain, pre-emptive vaccination was not effective, van Andel said.
Meanwhile, Biosecurity New Zealand was confident a recent slip-up at the border involving a traveller returning from Bali was an isolated incident.
A farmer travelling from Bali via Melbourne a fortnight ago was deemed low-risk when she arrived in Christchurch - and was not asked to go through additional open bag searches and footwear treatments.
Arrivals from Indonesia must have their bags checked and wash their shoes in disinfecting baths.
Deputy director-general of Biosecurity Stuart Anderson said that applied to all arrivals who had travelled to Indonesia in the past 30 days and she should have been properly checked.
"The overall risk from Indonesia still remains low, but there are extra measures in place," he said.
"We do believe this was an isolated incident, it's disappointing that the proper process wasn't followed and we've done everything we can to make sure that that doesn't happen again."
There were two other passengers on the same flight that were also returning from Indonesia, who went through the proper biosecurity processes, Anderson said.
"We know from across the airports that the process is working well, we've had good feedback from other passengers, and our records show that numbers that are in line with the numbers of passengers from Indonesia are going through our screening process."
Border staff have been reminded they need to follow the right processes, he said.
- RNZ
