A NSW horse has died from the Hendra virus, prompting authorities to quarantine a property in the state’s north

Hendra virus has killed a horse in northern NSW, causing authorities to quarantine a property as they run tests on its stablemates and the five people who handled the animal.

It’s the first case of Hendra discovered in NSW this year.

“The 31-year-old stockhorse gelding died overnight on Thursday after being found in a dam earlier that day and receiving treatment from a private veterinarian for very low body temperature,” NSW deputy chief vet Therese Wright said in a statement.

“Three people who handled the horse plus the veterinarian and an assistant are being assessed and monitored by NSW Health.”

In recent weeks no horses have moved off the property, west of Murwillumbah, and there are no dogs or cats about, Ms Wright added.

The paddock where the horse was kept “has regular flying fox activity,” she said.

Horses are believed to contract the Hendra virus from feed contaminated by urine, saliva or birthing fluids from flying foxes.

“Do not place feed and water under trees and cover feed and water containers with a shelter so they cannot be contaminated from above,” Ms Wright said.

Hendra virus was found in four horses and a dog across four separate mid-north coast properties last year.

“Winter is the season when horses have been infected with Hendra in NSW in the past so now is the time to get a vaccine booster for your horse,” Ms Wright said.

In Queensland four people have been killed by Hendra virus since 1994.

And in December councils across the state were given permission to trim trees and use smoke, lights and loud noises to drive flying fox colonies away from urban areas without needing a permit.

“If a horse becomes sick, owners should contact their veterinarian immediately,” Ms Wright warned.