The potentially deadly Hendra virus has spread further south with the NSW Department of Primary Industries (NSW DPI) confirming a case in the New South Wales Hunter region.

Key points: A horse has had to be euthanased after contracting Hendra virus near Scone, NSW

A horse has had to be euthanased after contracting Hendra virus near Scone, NSW The case occurred in the heart of the largest thoroughbred breeding area in the Southern Hemisphere

The case occurred in the heart of the largest thoroughbred breeding area in the Southern Hemisphere Since 1994, four people and 83 horses across Queensland and NSW have died from the virus

An unvaccinated mare contracted the virus late last week at a property near Scone and had to be euthanased.

DPI senior veterinary officer Paul Freeman said health assessments had been conducted for other horses and people at the property, where about 10 people had come into contact with the horse.

"It's not a highly infectious disease, so the risk to other horses is fairly minimal," Mr Freeman said.

The NSW Department of Primary Industries' senior veterinary leader Paul Freeman is disappointed that there hasn't been a greater number of horses vaccinated against the Hendra virus. ( ABC Rural: Kim Honan )

"The big concern with Hendra is the human health risk.

"The procedures we take are to ensure there is no human exposure wherever possible to infected areas.

"New South Wales health have undertaken risk assessments, they look at all the details of what interaction there was with the horse."

No movement on or off the property will be allowed for three weeks.

Southernmost case on record

The last outbreak of Hendra in NSW was an unvaccinated horse on a property near Tweed Heads — right on the Queensland border — in September 2018.​

What is the Hendra virus? Potentially fatal virus that can spread from fruit bats to horses to humans

Potentially fatal virus that can spread from fruit bats to horses to humans Virus is named after the Brisbane suburb where it was first detected in 1994

Virus is named after the Brisbane suburb where it was first detected in 1994 It was detected in a dog in 2011 and another in 2013, but is known only to occur naturally in flying foxes How is it spread? Horses usually contract Hendra virus by eating food contaminated by bat urine or saliva

Horses usually contract Hendra virus by eating food contaminated by bat urine or saliva Virus can be passed to humans exposed to high levels of an infected horse's bodily fluids

Virus can be passed to humans exposed to high levels of an infected horse's bodily fluids Human to human, bat to human, bat to dog, or dog to human transmission are unheard of What are the symptoms? Humans get flu-like symptoms — fever, sore throat, headache — that develop into meningitis or encephalitis

Humans get flu-like symptoms — fever, sore throat, headache — that develop into meningitis or encephalitis Horses suffer fever, increased heart rate and nervous system failure

Horses suffer fever, increased heart rate and nervous system failure Horses can be vaccinated against the disease Source: NSW Health

It has been more than two years since a case in Queensland, when a horse died from Hendra on a property in the Gold Coast hinterland in May 2017.

Prior to the case in Scone, the southernmost detection of the virus was near Kempsey on the NSW Mid North Coast in 2013.

Since 1994, four people and 83 horses across Queensland and NSW have died from the virus.

Be alert, not alarmed

The presence of the Hendra virus in the Hunter — the heart of the largest thoroughbred breeding area in the Southern Hemisphere — has put the industry on alert.

Hunter Thoroughbred Breeders Association President Cameron Collins urged horse owners who had not yet vaccinated against the virus to consider doing so, but said there was no particular risk for local thoroughbreds.

"This horse was located well away from the general thoroughbred breeding area," Mr Collins said.

"The general message is horses and flying foxes do not mix, and horse owners should be very diligent about keeping their horses away from flying foxes.

"The Hendra Virus vaccine is an excellent vaccine it has very good protection against the disease."

While the Hendra vaccination has been contentious, experts are encouraging horse owners to consider it following the recent case near Scone. ( ABC Rural: Jennifer Nichols )

To vaccinate or not

The Hendra vaccine has come under fire for expense and causing illness from some horse owners.

Last year horse owners launched a $53 million law suit against the pharmaceutical company responsible for developing the vaccine.

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The owners, from New South Wales and Queensland, claimed that Zoetis Australia PTY LTD did not provide adequate warnings about the potential side effects of the vaccine.

Scone eventer and horse breaker Blair Richardson had stopped vaccinating his horses after they reacted to it.

However, Mr Richardson said he may reconsider that decision with Hendra now showing up so close to home.

"I was surprised because I was always led to believe it was always further north and when you hear about something in your own district, it is a concern," he said.

Scone eventer and horse breaker Blair Richardson is considering vaccinating his horses as Hendra shows up close to home. ( ABC News: Cecilia Connell )

"I think now I will look into it [the vaccination] more.

"Having something local always makes you go back, look into it again and re-evaluate."