DPI staff were busy last week containing a massive outbreak of foot and mouth disease in the Goulburn Valley - but relax, it was only a drill.

The training exercise, code-named DIVA (distinguishing infected from vaccinated animals), involved more than 150 professionals from Tuesday to Thursday - including veterinarians, animal health officers, industry representatives and other government agencies.

DIVA placed DPI staff in the middle of a disease outbreak scenario, where new issues and problems surfaced every few hours.

DIVA scenario writer Roger Paskin said the staff containing the "outbreak" had their hands full.

"We've set up a script, a huge script which involves hundreds of cases and thousands of properties all over the Goulburn Valley," Mr Paskin said.

"They're walked into a scenario where there's a huge outbreak of foot and mouth disease and they have to deal with the different issues we throw up."

Mr Paskin said the exercise was not a one-off novelty.

"Victoria does two outbreak simulations every year; they're usually small, but every couple of years we simulate a major outbreak," he said.

"This is one of the biggest we've ever had."

This week's DIVA operation was an essential part of the DPI's training to manage a complex biosecurity emergency - and according to Mr Paskin, the Goulburn Valley is the perfect place to simulate the outbreak.

"With the volume of dairy cattle we have here, the Goulburn Valley would be the worst place for an outbreak to occur," he said.

DPI chief veterinary officer Hugh Millar said training exercises such as DIVA were important for Australia's future.

"An outbreak of FMD would mean Australia would lose important export markets for livestock and livestock products, resulting in potential losses of $15 billion a year," Dr Millar said.

Dr Millar said there were measures available to prevent an outbreak.

"Vaccination would be a tool to help control the spread of the disease . . . but there would be no escaping the fact that infected animals and herds would be slaughtered," he said.