The presence of a new strain of the rabbit calicivirus (Rabbit Haemorrhagic Disease Virus 2 or RHDV2) in New Zealand has been confirmed by MPI. There has, at this stage, been just one confirmed case in a single wild rabbit found on a Marlborough farm. However, the virus can spread rapidly and it is not known how widely the virus has already spread; it may already be widespread within New Zealand.
The Rabbit Haemorrhagic Disease Virus affects rabbits and the European hare. There is no danger to human health or other species of animals but companion rabbits are at risk.
There is currently no vaccine in New Zealand that provides protection against RHDV2 but MPI has stated that they are working to import a vaccine that can be used to protect companion rabbits. Rabbit owners should keep in touch with their veterinarian to find out when the vaccine is available and, when possible, have their rabbits vaccinated.
RHDV2 is a different virus strain to RHDV1-K5. RHDV1-K5 is the RHDV virus strain that was intentionally released in March and April. It is not known how RHDV2 infected the rabbit population here in New Zealand. Although RHDV2 is widespread in Europe and Australia, MPI has said that “the strain was not brought in from Australia because it is sufficiently different from the RHDV2 strain prevalent there. They have also said that they “can also rule out that the new strain came in with the RHDV1-K5 strain which was released nationwide in a planned rollout through March and April because of extensive testing at the time."
This means that there are now 3 different strains of RHDV present in NZ that we know of: the original RHDV1 v351, RHDV1-K5, and RHDV2.
The vaccine currently available in NZ (Cylap) is effective against RHDV1 v351 and research with small numbers of rabbits indicates that this vaccine will also provide protection against RHDV1-K5. Maintaining up to date vaccinations with Cylap, along with measures to reduce the potential exposure of rabbits to the virus, are currently the recommended steps to try and keep pet rabbits safe from RHDV1 v351 and RHDV1-K5. So our recommendation is still that all rabbits should be vaccinated with Cylap and kept up to date with this vaccination.
There is a vaccination for RHDV2 available in Europe but we do not have it here in New Zealand yet. MPI has said that they are working to import the latest vaccine for the RHDV2 strain from France. They expect the first 1,000 doses to be in the country next week and are working with importers to secure a long-term supply. So our recommendation is that rabbit owners keep in close contact with their veterinarian and get their rabbits vaccinated with the RHDV2 vaccination as soon as it is available.
For now, the advice for rabbit owners to help protect their rabbits against Rabbit Haemorrhagic Disease Virus is to:
- Contact your veterinarian for up-to-date advice about the best way to protect your rabbit from the virus.
- Prevent indirect and direct contact between domestic and wild rabbits.
- Avoid cutting grass and feeding it to rabbits if there is the risk of contamination from wild rabbits. Also be careful of fresh vegetables as some may be grown in areas contaminated with RHDV.
- If you are in contact with rabbits other than your own, wash your hands with warm soapy water between handling rabbits.
- Good insect control is also important and will help reduce the risk of exposure to the virus. Insect control could include insect-proofing your rabbit’s enclosure or keeping your rabbit indoors.
- Often the best way to prevent contact between domestic and wild rabbits, and avoid exposure of domestic rabbits to insects carrying RHDV, is to keep domestic rabbits indoors.
- Clean anything that rabbits come into contact with by using an agent such as 10% bleach, 10% sodium hydroxide, or Virkon (which is available from your local veterinarian).