In 2016, we wrote this blog post and below we include some FAQs and other more up to date and technical information.
Is vaccination necessary?
This will obviously involve assessing the risk to the individual rabbit(s), but the wide geographical range of the disease, and the reported losses of several hundred rabbits throughout the UK, as well as DNA fingerprinting as confirmation of cause of death in many sampled, suggests that vaccination is strongly advisable. Many cases have been confirmed throughout the UK, so you cannot assume you are in a ‘safe’ area. Additionally we believe that RVHD2 is significantly under reported. Because RHD2 doesn’t always look like classic RHD1, a rabbit could be taken into hospital looking ill, but nobody would necessarily think to treat that potentially infectious case for RHD2..
Do existing RHD1 vaccines work?
Because the mortality rate is lower with RHD2, any test using a small number of rabbits could easily show protection just because none of them were going to die anyway. There is some anecdotal evidence that RHD1 vaccines have some short term effect, but nothing peer reviewed. Le Gall-Recule (2013) showed that cross immunity between RHD1 and 2 was, at best, partial.
Do RHD2 vaccines work?
Eravac is licensed to produce full immunity 7 days after vaccination. Filavac produced good immunity (full protection) against RHD2 in challenge studies.
How will you get it from your vet?
Please only go through your vets, rather than contacting wholesalers. If your vet does not stock an RHD2 vaccine, please direct them to our website, and, if they want to, they can contact us directly for the most up to date information and any assistance they need.
What dose regime is suggested?
Standard advice with immunological products not licensed for simultaneous administration is to space them out by at least 2 weeks. The duration of immunity has been established at at least 12 months, in laboratory conditions in healthy rabbits, for Filavac. The manufacturer’s advice is to administer a single dose of the vaccine, followed by annual boosters in low risk situations, and 6 monthly in the case of breeding does at high risk.
Eravac is licensed from 30 days of age in pet rabbits, so in outbreaks can be given then, and again at 10 weeks, or just from 10 weeks in lower risk situations, and it is recommended that any other vaccine is given 15 days apart. Duration of immunity is proven at 9 months with challenge and 12 months with serology. Eravac is licensed in pregnancy and for pet rabbits. Eravac is also licensed to reduce viral excretion and shedding which is important in an outbreak.
Currently, with Eravac showing protection for 9 months in challenge studies, in high risk situations, I would advise vaccination at 9 month intervals if using this product.
In the UK, I would suggest that high risk situations include rescue centres and breeders, unless they have a strict quarantine policy, and those rabbits which have greater contact with wild rabbits, as well as any geographical location where cases have been reported recently. All other rabbits are likely to fall into the lower risk category, requiring annual re-vaccination.
What does the vaccine cost?
Here at the RWAF we are not able to monitor or affect the prices charged by veterinary practices. It’s worth pointing out that the price of the vaccine may vary widely between practices due to pricing structures, and due to the caseload of rabbits that they see. If they are able to make use of larger vaccine vials, the cost may be shared across more rabbits and reduced, but this is not often possible, as it requires enough rabbits to be seen in a 2 hour window during which the vial may be used.
What if I buried my pet rabbit and now wonder if it was RVHD 2, will the ground be infected and a risk to my other rabbits? (How should bodies be disposed of?)
There is not enough information out there to know the correct answer to this. We know it can live for 200 days in ideal conditions, so there is in theory a potential risk but we are speculating here. The best way to dispose of the body of any rabbit that died a sudden or unexplained death is to ask your vet to get it cremated for you. Double wrap them in plastic, and disinfect the outside, before taking to your vet, to reduce the risk of disease spread.
Once rabbits have recovered from RVHD2 do they still carry it? Do they still shed? Can I bond to another rabbit safely without risking them?
There is not enough information known about RVHD2 to know the correct answer to this with any certainty. In theory they should be safe to bond after 200 days, in practice it may be safe sooner than this, but we really don’t know.
Can you recommend a cleaning protocol?
90% of any disinfection is cleaning, that is the most important aspect. After thorough cleaning of the area to remove any scale or residue, use Ark-Klens , which is a benzalkonium chloride disinfectant and as such it should be effective against EC and myxi, to routinely disinfect the housing. Periodically use Virkon (as an inorganic peroxygen compound) to kill any other viruses. Anigene HLD4V has been confirmed as effective against RVHD2 at a dilution of 1:50. It is important that the correct dilution is used. Note: Other benzalkonium chloride disinfectants and inorganic peroxygen compounds may be available, in addition to those named above.
Other than vaccination can I prevent my rabbit getting RHD? Will they get it from hay?
They are very unlikely to get RHD (1 or 2) or Myxomatosis from hay or barn dried grass. Risk / benefit analysis would be in the favour of feeding these foods. Foraged foods may potentially carry RVHD. Try to obtain plants from areas out of the reach of wild rabbits, and do not collect forage from areas of known wild rabbit RVHD infection. Biosecurity advice was given in the a webinar but sadly this is no longer available, so it is summarised here: Use foot dips or change footwear between going outside, especially into areas frequented by wild rabbits Quarantine new animals, feed them last, use new equipment such as bottles / bowls for them. Barrier nurse any suspicious cases Try to exclude wild rabbits and unless they can be excluded from the garden consider stopping the practice of moving pens around the garden and even consider a double fence round rabbit runs.
What are the risks of “over-vaccination” and vaccine ingredients?
The risk with Eravac causing skin and subcutaneous tissue damage is much lower than with older, oil based vaccines, as although there is some oil in the vaccine, and this stimulates immunity, the oil droplets are themselves contained within water soluble material, protecting the tissues from direct contact. Eravac ONLY protects against RHD2, and so no potential “over-vaccination” occurs.
Eravac is an inactivated, adjuvanted vaccine, and so cannot lead to clinical RVHD in the animal. Furthermore, it is now licensed to provide reduction in viral excretion and diffusion, so especially important in outbreaks.
Vaccinating with an RHD 1 and 2 vaccine (Filavac), 1-2 times per year, on top of an existing RVHD1 and Myxomatosis vaccine (Nobivac), obviously increases the vaccine frequency and amount given to each rabbit. This is not perfect, but the alternative is missing out one of these vaccines, and the risk of “over-vaccination” is considered lower than the risk of insufficient protection.
Concerns are often raised about vaccine ingredients (adjuvants and excipients) such as aluminium hydroxide and sodium metabisulphite. This is too large a topic to discuss here, but, without dismissing these concerns out of hand, and after weighing the risks against the benefits, vaccination has a strongly net positive benefit against the diseases discussed here. There are known vaccine side effects discussed in the data sheets for these vaccines. They are usually limited to small local temporary skin reactions, and temporary mild lethargy, but if your rabbit becomes ill, especially if they go off their food after vaccinating, please call your vet.
How to make a decision about vaccination.
You should discuss the risks and benefits of vaccinating your rabbit(s) with your vet, who is best placed to advise you whether to vaccinate and how often. There is a risk to any animal (or person) to having any vaccination, which is why animals (or people) should only be vaccinated if they are healthy.
Titre testing against this strain is not commercially available, at least at present in the UK.
Can both vaccines be given together?
No, there should be at least 2 weeks between Nobivac Myxo-RHD vaccine and either Filavac or Eravac.
Good veterinary practice dictates that there should be a 2 week period between vaccinations
None of the vaccines has been tested in combination so it’s unknown if full immune responses can be achieved if the vaccines are given together.
Vaccines should only be given to healthy pets and should not be given at the same time as any surgical procedure.
Refs: Joana Abrantes, Wessel van der Loo, Jacques Le Pendu and Pedro J Esteves (2012) Rabbit haemorrhagic disease (RHD) and rabbit haemorrhagic disease virus (RHDV): a review Veterinary Research 2012, 43:12 doi:10.1186/1297-9716-43-12 Kevin P. Dalton, Inés Nicieza, Ana Balseiro, María A. Muguerza, Joan M. Rosell, Rosa Casais, Ángel L. Álvarez, and Francisco Parra(2012) Variant Rabbit Hemorrhagic Disease Virus in Young Rabbits, Spain Emerg Infect Dis. 2012 Dec; 18(12): 2009–2012. doi: 10.3201/eid1812.120341 D. G. Westcott and B. Choudhury Rabbit haemorrhagic disease virus 2-like variant in Great Britain Veterinary Record doi:10.1136/vr.102830 Joana Abrantes, Ana M. Lopes, Kevin P. Dalton, Pedro Melo, Jorge J. Correia, Margarida Ramada, Paulo C. Alves,Francisco Parra, and Pedro J. Esteves New Variant of Rabbit Hemorrhagic Disease Virus, Portugal, 2012–2013 Emerg Infect Dis. 2013 Nov; 19(11): 1900–1902. doi: 10.3201/eid1911.130908 Detection of a new variant of rabbit haemorrhagic disease virus in France G. Le Gall-Reculé et al February 5, 2011 | Veterinary Record | 137-138 doi: 10.1136/vr.d697 Emergence of a new lagovirus related to Rabbit Haemorrhagic Disease Virus Ghislaine Le Gall-Reculé et al (2013) Veterinary Research 2013 44:81 DOI: 10.1186/1297-9716-44-81
Other useful sources of information: http://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1005087 http://www.iucn-whsg.org/RabbitHemorrhagicDiseaseInEurope https://www.harcourt-brown.co.uk/articles/infectious-disease/rabbit-haemorrhagic-disease Webinar: http://therabbitvet.com/webinar/vhd-rhd-2-update-rabbit-haemorrhagic-disease
We should all remember that we (and our rabbits) owe a huge debt of thanks to our Specialist Veterinary Adviser, Dr Richard Saunders who worked long and hard to secure permission from DEFRA to import vaccines from continental Europe that protect our rabbits against RVHD2. Without his very hard work and dedication we in the UK would not have Filavac from France nor licences that also allow us to import Cunivak RHD from Germany and Cunipravac from Spain should we need to. This is alongside all the other things he does for rabbits and the huge input he has had into composing the information on this page and frequently updated blog posts.