How to deal with an outbreak of RHD

It can be difficult to know what to do once RHD is confirmed as the cause of death in an establishment where there are other rabbits. There are some immediate considerations.

Vaccination

Vaccination is the only way to control RHD and, ideally, all rabbits over 4 weeks of age should be vaccinated on any premises, let alone one where RHD has been confirmed. Vaccines against RHDV1 and RHDV2 are safe and effective but the time it takes them to become effective is an important consideration in the face of an outbreak. Nobivac Myxo-RHD plus (MSD Animal Health) takes 3 weeks. Filavac (CEVA Animal Health) and Eravac (Hipra Laboratories) take 7 days.

Lockdown

Lockdown of infected premises is the most responsible way forward if a rabbit dies from RHD in a multi-rabbit establishment. Ideally, no rabbits should go in or out of these premises and owners should take care not to spread infection. Separate clothing, especially footwear for dealing with the rabbits is recommended. It is essential to stop taking rabbits to shows or selling or rehoming them. There may be rabbits incubating the infection that could spread RHD to other rabbits. It is difficult to eliminate cross-infection. The source of the infection is usually unknown and could still be present (e.g. contaminated food or neighbouring wild rabbits).

It is hard to know how long lockdown should continue. Four months from the date of the last death is recommended. Vaccination of surviving stock is essential. A temporary halt in breeding programmes may be necessary for breeders to eliminate infection.

Disinfection

Disinfection is only effective when it comes into contact with the RHD virus. Organic material, such as food, bedding or faeces, will protect the virus and may also inactivate the disinfectant.  Every disinfectant is more effective when applied to a clean dry surface. A good overview of disinfectants that are available in the UK and their use in rabbits is available online (Lord, 2018). For RHD, any viricidal disinfectant that is effective against feline calicivirus should be effective against RHD. It should be used according to the manufacturer’s guidelines. Virkon (Vetoquinol) at a dilution of 2% is recommended. The manufacturers say that mixing 2 tablets in 500mls in a spray bottle and spraying the underside of clean shoes is more effective than a footbath. Footbaths quickly contain so much organic material that they become ineffective.