Invasive Animals CRC national release of new strain of Rabbit Haemorrhagic Disease Virus (RHDV1 K5) in Tasmania – 2017
To combat the threat of rabbits within Australia, the national release of a Korean strain of Rabbit Haemorrhagic Disease Virus (known as RHDV1 K5) was carried out in March 2017.
The release of RHDV1 K5 comes after more than 10 years of testing through the Invasive Animals Cooperative Research Centre RHD Boost project and includes participation by over 600 community groups and land managers across Australia, including ten sites in Tasmania.
Biosecurity Tasmania administered the RHDV1 K5 bait to the Tasmanian site land managers under permit requirements. The initial release took place at the TasmaniaN sites in in March/April 2017 - with a follow up release carried out in May/June 2017.
As part of the project, the public is being urged to get involved by helping to track the spread of the virus through downloading the RabbitScan (FeralScan) smart phone app, where you can easily report evidence of disease to assist land managers across Australia understand the movement of the virus.
To report sightings of rabbits or evidence of disease in your region visit www.rabbitscan.org.au
or download via the iTunes or GooglePlay stores through searching for ‘FeralScan’.
Visit the PestSmart
website for more details on the national release of RHDV1 K5.
RHDV1 K5 only affects European rabbits and is a naturally occurring variant of RHDV1 from Korea. RHDV1 K5 poses no risk to human health or other non-target species. However, domestic rabbits and farmed rabbits may be affected. It is recommended that domestic rabbit owners and commercial rabbit breeders consult their local veterinarian about vaccinations and provide additional protection against the virus by keeping rabbits inside or in insect-proof enclosures.
For further information on Rabbit Haemorrhagic Disease Virus, please contact Biosecurity Tasmania: Northern Tasmania: 03 6421 7635 and Southern Tasmania: 03 6165 3265.
Rabbit haemorrhagic disease virus (RHDV)
European rabbits are an invasive animal which has caused large scale economic and environmental damage in Australia. They have a wide range of impacts including competing with livestock for pasture and decimating food crops. The rabbit population is substantial in many areas of Tasmania, particularly in and around urban areas.
Biosecurity Tasmania uses rabbit haemorrhagic disease virus, also known as rabbit calicivirus, to undertake localised rabbit control where rabbit numbers are causing significant environmental impacts and the use of other control methods by landowners is not suitable.
Rabbit haemorrhagic disease virus (RHDV) is a viral disease which
only affects European rabbits. The virus probably originated from a less virulent form present in natural rabbit populations for many years. It was first reported in China in 1984 and soon after in other countries in Asia and Europe and in Mexico.
The virus was introduced to Australia in 1995 and Tasmania in 1997. Since then it has since spread throughout most of the country, mainly by natural spread.
Delivery method for RHDV
RHDV can be introduced into rabbit populations by trapping rabbits and injecting them with the virus or by introducing the virus on a bait.
(See information on the Australian Pesticides and Veterinary Medicines Authority website.)
In Tasmania, the virus is introduced on carrots following pre-feeding (using carrots) to attract rabbits to the release site. Use of the virus is restricted to trained Biosecurity Tasmania staff and other people who are assessed as competent.
RHDV is widespread in rabbit populations in Tasmania. Introduction of virus may not be a satisfactory control option in all situations. It should only be considered for use in areas where:
- other control techniques are unsuitable; and,
- there has been no evidence of RHDV for over 12 months.
Effects on rabbits
A rabbit infected with the virus will develop the disease within one to three days. Greater than 75 per cent of infected rabbits will die from the disease. RHDV infects many organs including the lungs, gut and liver causing acute hepatitis that can kill the rabbit within 48 hours by causing rapid and widespread blood clotting.
Generally, only rabbits older than 12 weeks are susceptible to the virus. Rabbits younger than 12 weeks that are infected are less likely to die than older rabbits. Young rabbits that survive infection become immune adults.
It should be noted that some rabbits die very quickly from the disease and can look relatively normal externally. They may also show very few visible changes to the internal organs.
Effects on other species
There is no scientific evidence that RHD infects any other animals.
Australia has tested for the virus in at least 33 representative animal species, domesticated and wild, native and feral. All were given large doses of the virus and no signs of infection were observed. Worldwide, 43 different species have been tested and the virus did not infect any of them.
No evidence of RHDV infection has ever been reported for humans. International laboratories confirm that human infection with RHDV is not known to occur and no health effects have been seen, even in people working very closely with the virus.
Vaccine for domestic rabbits
Effective vaccines to protect domestic rabbits from RHDV have been developed. These can be accessed through local veterinary clinics. Domestic rabbit owners should consult their local vet about vaccination.
The RHDV vaccine is safe to use on pet and farmed rabbits. As with any vaccine for animals or humans, only vaccinate your rabbit when it is healthy.
Your veterinarian can advise on other issues to be aware of when having your rabbit vaccinated.
Protecting your pet and farmed rabbits from RHDV viruses
A recent outbreak of another virus known as RHDV2, for which the origin is unknown and there is no available vaccine, may put pet and farmed rabbit stock at risk in Tasmania. Strategies for protecting your pet and farmed rabbits from RHDV viruses can be found on the DPIPWE website.