People with pet rabbits are being urged to have them vaccinated before a planned release of calicivirus that aims to reduce the number of feral rabbits.
Calicivirus will be released in the northern Sydney region between late March and early April by the Greater Sydney Local Land Service.
Feral rabbits are a declared pest that cause major environmental and agricultural damage.
Calicivirus, which is also known as rabbit haemorrhagic disease virus (RHDV), is mainly spread by contact between rabbits and by insects.
However, the virus is species specific and cannot harm humans or any other animals.
Those who own pet rabbits should talk to their vet and maintain a vaccination program.
In largely urban areas like Hornsby Shire calicivirus has been proven to be the most effective and humane method of rabbit control.