Introducing a new rabbit after an outbreak of RVHD2

“How long should I leave it before introducing a new rabbit after an outbreak of RHD2?” We are regularly asked this question or a variation of it. It is a really difficult question to answer for several reasons.

The science:

Firstly, the virus is incredibly resilient in the environment, at least in ideal experimental conditions, e.g. in organ suspensions held at 4C, where it can survive for more than 7 months. In less artificial conditions, e.g. cool, not dry, protected from UV light, and in/on organic material, e.g. carcasses, it has been shown to survive for at least three months (as the experiment stopped at that point, it could survive for longer than this). Less optimal conditions, where the virus is cooled but kept dry, give survival times of less than one month.

Another study showed the excretion of the virus for two months in rabbits that recovered from the virus.

As a result, quarantine periods of between a month and seven months have commonly been suggested before exposing a new rabbit to previously infected or in contact rabbits or environments where the virus has been shed. It is difficult to propose a one-size-fits-all exact period of time to guarantee biosecurity without suggesting a potentially significantly excessive duration.

In practice:

We suggest at least two months before bringing a rabbit into contact with the survivors of an outbreak.

We suggest thorough cleaning and disinfection of any non-porous inanimate objects or surfaces in contact with infected animals and either disposal of or cleaning following soaking in disinfectant for porous objects. Cleaning of cracks and corners of hutches, etc, is vital. Anigene and Virkon are both considered suitable for this type of cleaning, but make sure you follow their instructions.

Grass and earth are difficult to disinfect, but exposure to high temperatures and UV light in sunlight should inactivate it within approximately a month (although particular care should be taken if there are microclimates of moist, cool conditions with organic material present: faeces, food, hay, etc., should be removed to allow exposure of the surfaces).

A period of at least 3 months is probably sufficient to eliminate the virus in bodies or protected suitable organic material (e.g. parts of bodies) in all but experimentally perfect conditions, and so a widely used period of 4 months is understandable.

However, this needs to be balanced against the welfare issues of sole or unsuitably housed rabbits. Vaccination with a suitable RHD2 vaccine can reduce the risk (although never to zero, as no vaccine is 100% protective).

Summary:

It is impossible to give a reply that is suitable for everyone, and you should discuss your situation with your vet. However, our general advice is:

• Make sure all rabbits are vaccinated against RVHD2
• Thoroughly clean the area
• Wait at least two months before introducing another (vaccinated) rabbit.

The onset of immunity can be up to three weeks (depending on the vaccine), so introduction to the premises should be at least three weeks post-vaccination.