Rabbit haemorrhagic disease virus (RHDV) has been used in Australia for more than 20 years to minimise the impacts of introduced European rabbits (Oryctolagus cuniculus) on farming and the environment. In most susceptible adult rabbits the disease progresses rapidly from fever and lethargy to death within 48–72 hours of infection. RHDV has a high mortality rate resulting in the death of 70–90 per cent of susceptible rabbits.
The RHDV1 Czech v351 strain has been available to authorised users as a biological control agent since 1996. A strain introduced in 2017, known as RHDV1 K5, is now available for purchase.
Estimating the prevalence of immune wild rabbits prior to release of biocontrol strains is recommended. This is best achieved by collecting cardiac blood from 8–10 freshly shot wild rabbits in the area where the virus is proposed to be released. Blood is usually collected using a syringe and needle into a Vacutainer® tube. The blood should be sent to the Elizabeth Macarthur Agricultural Institute (EMAI) with an accompanying specimen advice form. A high sero-prevalence in the rabbits is an indication that release of the virus is not likely to be successful in reducing numbers.
In NSW, only people that have undergone appropriate training and are approved authorised control officers (ACOs) by NSW Department of Primary Industries can purchase RHDV. Landholders should contact Local Land Services.
Rabbit haemorrhagic disease virus, RHDV1 K5, is available in freeze-dried form from NSW Department of Primary Industries Virology Laboratory. The RHDV1 Czech v351 strain is also available. ACOs can obtain RHDV by contacting EMAI: firstname.lastname@example.org or (02) 4640 6337.
RHDV should only be used according to the instructions supplied with the product. Do not release RHDV into areas where young rabbits are present as they are much less likely to die because of RHDV but the exposure to the virus at this age can provide lifelong immunity. Pre-feeding of non-treated bait is an essential step to allow rabbits to become accustomed to eating bait material, such as carrots and oats. Rabbits should be fed carrots or oats on at least two to three days prior to the release of RHDV. A standard operating procedure for the bait delivery of RHDV1 K5 is available from the PestSmart website.
Information about RHDV1 K5 and general rabbit management is available from the PestSmart website, including:
Please note that warren destruction by ripping or other means should be considered as part of effective rabbit control in the months following the introduction of RHDV. Destruction of existing warrens has been shown to reduce the chance of rabbits reinvading a site after the population has been reduced.
More information about the different RHDV strains is available from the Australian Veterinary Assocation: www.ava.com.au/rabbit-calicivirus