Veterinarians and quarantine officials across the north of the country are on alert amid warnings Australia is at risk of an outbreak.

Australia is currently free of rabies but experts fear if the virus is somehow carried to areas around the Top End - which are closest to Bali - it could spread rapidly in an unprotected dog population around settlements, towns and in the wild.

Bali is in the midst of a dog vaccination program after the deaths of more than 100 people since rabies entered the island in 2008.

The virus is highly contagious and causes inflammation of the brain.

The Bali outbreak has been linked to a fisherman bringing his infected dog to the holiday island.

Australian Veterinary Association president Barry Smyth said the disease would spread rapidly if it were to enter Australia, as there is no vaccination program against rabies here.

“If it did find its way into Australia, it could create significant problems,” he said.

“Rabies can have a long incubation period, so someone who is bitten may not show signs for several weeks.”

Dr Smyth urged Australians travelling to Bali to stay clear of any unfamiliar animals.

Federal opposition leader Tony Abbott urged the government to do all it could to prevent the possible spread of rabies.

“It's important that we do all that we reasonably can by way of quarantine and other forms of bio-border protection to keep our country safe,” Mr Abbott said.

“Border protection is not just about stopping the boats. It's also about stopping disease and it's important the government does what it can.”

Independent group AMRICC, which works to improve the health of animals in communities across the north of Australia, said the potential for an outbreak in Australia was concerning.

The group of veterinarians and academics works with Aboriginal communities, including those in northern Western Australia, to address the growing population of dogs in settlements, and consequent health risks.

Spokeswoman Eileen Fletcher said the group was training people in those communities to become another line of defence against any threat of rabies.

“(The Australian Quarantine and Inspection Service) are doing their best, but there are a lot of empty beaches, and if a dog was to get here, there would be extremely rapid transmission,” she said.