The Ministry of Primary Industry’s announcement that a new strain of rabbit calicivirus (RHDV2) has been detected in a wild rabbit in Marlborough is worrying for pet rabbit owners.
While this strain has only been detected in one location, it is possible that RHDV2 is more widespread in New Zealand, but hasn’t yet been found in other regions. The potential to cause disease varies widely amongst RHDV2 strains. This newly reported strain of RHDV2 is not the same as the one present in Australia. It is not yet known what threat is poses to rabbit health, but it is possible that the virus could spread rapidly throughout New Zealand.
RHDV2 viruses can infect rabbits from 3-4 weeks of age and some strains have high death rates following infection. Rabbits infected with a RHDV2 strain that causes illness are often off their food and reluctant to move around for 3-5 days before dying. Sick rabbits are highly infectious to other rabbits.
The New Zealand Veterinary Association welcomes the support from MPI in urgently importing a registered vaccine, Filavac, for pet rabbits to provide protection from RHDV2. Until Filavac is available, rabbit owners are encouraged to discuss with their veterinarian the benefits of using a modified protocol of the current rabbit vaccine (Cylap RCD). It is thought that Cylap RCD can provide a degree of cross protection and may be useful if you believe your rabbit is at risk, and are not able to access the Filavac. The modified Cylap protocol involves beginning vaccinations at 4 weeks of age, and receiving boosters every 6 months.
In addition to vaccination, these measures will also reduce the risk of a pet rabbit contracting a calicivirus:
- Control insects (especially flies and fleas) as much as possible both indoors and outdoors. Flies are the main vector through which the virus is spread.
- Remove uneaten food on a daily basis so as not to attract flies.
- Keep your pet rabbit indoors where possible.
- Rabbit-proof your backyard to prevent access by wild rabbits.
- Regularly decontaminate equipment and materials (e.g. cages, hutches, bowls) with either 10% bleach or 10% sodium hydroxide.
- Limit contact with and handling of unfamiliar pet rabbits. Avoid rabbit shows or other events where rabbits may be present.
- Use good biosecurity measures (e.g. wash hands, shoes and clothing) after handling other people’s rabbits.
- Avoid cutting grass and feeding it to your rabbits if there is the risk of contamination from wild rabbits.
- Isolate new rabbits for 7 days before introducing to other rabbits.
- Rinse all leafy greens well before feeding them to rabbits. While feeding rabbits leafy greens remains a risk for introducing RHDV2, the benefits of feeding these is considered to outweigh the risks.
Source: NZ Veterinary Association