Queensland owners and trainers have been reminded to make sure their horses are vaccinated against the Hendra virus after a confirmed case in NSW.

A spokesperson for the Queensland Racing Integrity Commission said the NSW Department of Primary Industries had advised the deadly Hendra virus was confirmed in a horse at a property near Australia's horse capital, Scone in the Hunter Valley.

It is the most southern location the infection has been detected in Australia.

An unvaccinated mare on a Hunter Valley property developed neurological signs on June 7 three days after being confined to a yard and was subsequently euthanised.

A spokesperson said the department also confirmed the horse was not vaccinated and when she had a sudden onset of neurological signs, the owners contacted the animal diseases hotline.

QRIC Director of Animal Welfare and Veterinary Services, Dr Martin Lenz, reminded racehorse participants to follow good biosecurity practices and for trainers and owners to speak to their vets about vaccinating the horses in their care against Hendra virus.

"Vaccination remains the single-most effective prevention method," Dr Lenz said.

The virus surfaced in Queensland in the early 1990s and gained further prominence when trainer Vic Rail and several of his horses died.