NSW Department of Primary Industries (DPI) and Local Land Services (LLS) advise animals should be given an annual vaccination on these high-risk properties, which include districts bordered by Bourke and Moree to Albury and Deniliquin in the south.

NSW DPI senior veterinary officer, Amanda Walker, said anthrax is unpredictable as it can lie dormant in the soil for decades.

"Farmers should contact their LLS district vet to obtain advice specific for their properties," Dr Walker said.

"Anthrax is a serious disease that can kill stock of any age or class with no warning. Vaccination prevents anthrax from occurring and helps break the cycle of spore production.

"If vaccination is continued over time, spores in the environment will die, reducing the risk of anthrax occurring in the future."

LLS State Veterinarian, Scott Ison, said farmers can apply to use the vaccine through their LLS district veterinarian.

"Once the vaccine has been authorised, farmers can place an order with their local rural supplier or private veterinarian," Dr Ison said.

"Anthrax disease is caused by the bacterium Bacillus anthracis and affected stock often show few or no signs of ill health before they die.

"Farmers should suspect anthrax if animals die suddenly, as in many cases there may be no signs and the disease may begin with the sporadic deaths of single animals over a few days before building to dramatic losses in a very short time."

Anthrax is listed as prohibited matter under the NSW Biosecurity Act 2015 and is a notifiable disease in NSW.

Anyone who suspects anthrax must report it immediately by calling the Emergency Animal Disease Hotline, 1800 675 888.

More information about preventing anthrax is available on the NSW DPI website: www.dpi.nsw.gov.au/biosecurity/animal/humans/anthrax or by calling Local Land Services on 1300 795 299.