The horse racing industry is bracing itself for an epidemic as the Hendra Virus continues to spread across south-east Queensland and northern New South Wales.

Biosecurity personnel believe that the virus may have spread unknowingly for the past two weeks before anybody realised.

A property at Mount Alford, 50 kilometres southwest of Brisbane, is the latest estate to be quarantined following two other confirmed outbreaks last week.

23 people are currently awaiting tests in order to find out whether they have contracted the deadly bat-born virus.

The Hendra Virus has a 57 per cent mortality rate in humans.

Neal Fearon, who is the owner of a quarantined property near Boonah, is asking for horse owners to be cautious.

“We thought we were clear from any bat colonies,” he said.

“Speaking to veterinarians over the past period of time, it could be just a simple case of a bat flying over our property and dropping some droppings

“One of our horses has ingested it and this is the outcome.”

Another one of those at risk is veterinarian Peter Prenzler, who euthanized a horse on June 20 that was later found to have been suffering from the disease.

Dr Prenzel initially misdiagnosed the horse and it wasn’t until he was called back to the property of Friday night that he suspected the worst.

He was not wearing any protective clothing or equipment when he euthanized the first horse.

“It was a shock to the system, because I could have taken a virus that’s got a very high death rate in humans,” said Dr Prenzler said.

“I could have been exposed to the virus for 13 days now, which is smack bang in the middle of the incubation period.

“(It’s) an anxious time. My wife said she’s not going to let me see any more horses. But that won’t happen unfortunately because of my job.”

The virus has been detected on only 17 occasions since 1994 and has killed four of the seven people who have contracted it.

Dr Prenzler said that veterinarians did not often use protective equipment when treating horses because it proved to be a hindrance to their work.

“It’s like when you go and see your GP,” he said.

“You’ve got the flu, but he’s not going to greet you in all of his gear.

“I don’t think we can really change our approach to how we look at animals.

“Human doctors don’t change their approach when they sit in the surgery and look at people come in the door sick.”

The CSIRO’s Australian Animal Health Laboratory is currently in the process of developing a vaccine for Hendra Virus, but it may not be available for some time.