Rabbit calicivirus (also known as rabbit haemorrhagic disease or RCD) was introduced into New Zealand in 1997 illegally by farmers in a bid to reduce the wild rabbit population. In the following 20 years, the wild population has developed increased
immunity to this strain of the virus and so wild rabbit numbers increased dramatically again. A new strain of calicivirus (K5 - a more virulent strain) was introduced in 2018 by MPI into several locations in order to try and reduce the wild rabbit population . It is expected that the virus will eventually spread throughout the whole of NZ. During surveillance done in 2018 it was discovered that a third strain of RCD was present in NZ in both the North and South Islands. This third strain is a different type and so is not covered by the existed rabbit vaccine (Cylap) which has been used in NZ. MPI have now imported a new vaccine (Filavac) which protects against all 3 strains now known to be in NZ.
What does this mean for pet rabbits?
Whilst no vaccine can offer 100% protection it is your rabbit’s best defense against infection. The vaccine is usually given to rabbits around 10-12 weeks of age as younger rabbits are immune to the virus initially. Rabbits under 12 weeks of age will require a booster vaccination a month later but older rabbits only require one vaccination and then annual boosters. Rabbits that have been vaccinated with Cylap vaccine can be revaccinated with the new Filavac vaccine. Cylap vaccine is much cheaper than the new vaccine and can still be used but it will only protect against 2 of the 3 strains.
How is the virus spread?
Direct contact with infected rabbits isn’t needed to spread the virus. It can be spread on anything contaminated with urine/faeces or respiratory secretions from infected rabbits – this includes hay/straw, grass, clothing, shoes, people’s hands, hutches, used food/water bowls. Insects such as flies, fleas and mosquitos are also capable of spreading the virus. It is even thought it can spread via wind in certain conditions. Hay and straw should have been stored for at least 3 months before being used for rabbits to reduce the risk of virus spread, as the virus can survive for around 90 days in the environment. After handling other rabbits, owners should thoroughly wash their hands and change clothing preferably. Any cages and bowls should be thoroughly cleaned out with disinfectant or bleach before letting new rabbits use them.
What are the symptoms of disease?
Sudden death is the most common sign seen. Most affected rabbits die within 2-3 days of infection and many show no other symptoms beforehand. Some rabbits will go off their food and appear lethargic. The third strain of virus tends to have a longer period of illness prior to death.
What if I want to get a new rabbit after my previous rabbit died of possible calicivirus?
Preferably wait at least 3 months before getting a new rabbit. All cages and equipment should be thoroughly cleaned with disinfectant such as Virkon, Trigene or bleach solution (contact time of 10 minutes needed). Ideally vaccinate your new bunny as soon as it is old enough and keep up annual vaccinations.
Published Friday 9th of November 2018