The Pan Pacific veterinary conference in Brisbane has heard that the international movement of horses is behind the spread of equine influenza.
New Zealand is the only major horse-producing country in the world that is free of the disease.
The director of the equine research centre in South Africa, Alan Guthrie, told the conference that since horse flu entered the United States from South America in the 1960s it has been associated with major equine influenza outbreaks in countries all over the world.
The chief executive of the New Zealand Veterinary Association, Julie Hood, says it's the greatest threat to the horse industry here.
The country is only free of the disease, she says, thanks to robust quarantine regulations.
Ms Hood says New Zealand veterinarians are learning from their Australian counterparts how to respond to a horse flu outbreak if it does spread here.