A new strain of Rabbit Calicivirus (RHDV2) is spreading across Australia with confirmed cases in Paruna and Murray Bridge. This new virus strain is distinct from RHDV1, which was released in Australia in 1996 for the control of wild rabbits.

The impact on pet rabbits and rabbit farms is high and it can cause sudden death in young kittens (3-4 weeks) and a proportion of vaccinated adults.

Virus transmission is both by direct contact and indirectly via fomites or vectors, like blowflies, flies, mosquitoes and biting fleas. The virus causes acute liver failure.

The current vaccine for Rabbit Calcivirus is not fully protective against RHDV2. However, keeping domestic or pet rabbits’ vaccinations up to date is recommended to provide the maximum possible protection against this new strain. While an updated vaccine is being developed in Europe, a revised vaccination protocol is warranted for kittens, using the vaccine currently available in Australia. The suggested off-label regime is: vaccinate kittens at 4 weeks, then at 8 weeks, and again at 12 weeks, followed by yearly vaccinations. For breeding adults, a six monthly booster is recommended.