New vaccine

We are still getting enquiries about the new combined Myxi and RHD vaccine. The main concern expressed with the vaccine is the potential lack of protection against Rabbit Viral Haemorrhagic Disease Virus, in rabbits vaccinated with the new vaccine, if they have been previous vaccinated recently against myxomatosis, or have been infected with it and recovered. This has been raised as a concern because some rabbits which had received previous Myxomatosis vaccination in trials in continental Europe did not develop immunity against RHD following vaccination with the Myxo_RHD vaccine. The vaccines used predominantly there are based on the myxomatosis virus, whereas the current one used here is based on Shope Fibroma Virus. This has led to some uncertainty until recently as to the level of protection so obtained, and the best vaccination protocol to be used in rabbits that have had previous vaccinations. Recent work has been collated by the manufacturers, and demonstrates that at lower levels of vaccine content, there is not sufficient protection. However, at the levels that the vaccine contains, the vast majority of rabbits developed antibody levels that are protective against RHD. The vaccine is also known to produce cell immunity, in addition to antibody levels, which cannot be measured by blood tests, and these results are typical of an effective vaccine as used in other species. The only way to examine the vaccine effectiveness further would be to perform challenge studies. This would entail taking vaccinated and unvaccinated animals and deliberately subjecting them to RHD virus, which would kill the unprotected ones. For ethical reasons this is not ideal, and would perhaps be especially unfortunate since the new vaccine has been made without the need to culture the virus in live rabbit liver, as is necessary with previous RHD vaccines. Without wishing to endorse a specific product, we feel that vaccination against these 2 killer diseases is an important part of rabbit preventative health. Any tool which allows us to prevent death and suffering, especially when this is made easier and therefore more practical to achieve, by only involving one visit to the vets per year, is to be welcomed. We will be covering this in more detail in the next issue of Rabbiting On, due out early May – to make sure you don’t miss your copy please join and support our work, because A hutch is not enough: http://www.houserabbit.co.uk/join/index.php

Last FAQ

There were various questions about calcium levels in the diet, but we think an earlier post covers them all:

http://rabbitwelfare.blogspot.com/2011/06/calcium-content-and-diets.html

We are getting calls and e-mails about the new vaccine but feel that some of these questions would be better answered by the vaccine manufacturer themselves; so we hope to bring more FAQ in the next issue of Rabbiting On.

FAQ cont’d

The new vaccine is arriving in vet practices this week. The UK tests have been
completed and although we do not have the results as yet we will update everyone
when we do.
Q5)
I’m interested to know more about the new combined vaccine…and in particular
there’s something in the data information which suggests that if a bunny has had
the other myxi vaccine in the past, the VHD element of the new vaccine might not
work. I‘d be interested to now why this is. What does this mean in practice?
Will the new vaccine therefore only be used for first time bunnies, or will it
be used in conjunction with one of the former VHD vaccinations? What advice have
vets been given about this?
A5)
The new combined vaccine has been tested in rabbits given the continental
Myxi vaccine, and there were borderline low protective titres to VHD. This is a
different vaccine to what is used in the UK against Myxi so there is now work
underway to see if the UK Myxi vaccine interferes to the same degree, though
they expect it not to be a problem. We expect results shortly.

EC
Q6)
Are Trigene and Vanodine safe for use with rabbits and would they kill
EC?

A6) Vanodine
is an iodine based product, which claims to kill other spore based
bacteria/fungi etc, and so I would imagine it to be effective after cleaning as
per our cleaning protocol:
Thoroughly
clean 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.Note: Other benzalkonium chloride disinfectants and inorganic
peroxygen compounds may be available, in addition to those named
above.
Trigene
is safe at the dilutions recommended, and should be as effective as above
(product is claimed effective against spores, bacteria, fungi, mycobacteria and
viruses) assuming the above cleaning procedure is followed
beforehand).

Myxi outbreak and Ask the Expert.

We’d like to remind you once more about keeping vaccinations up to date. It’s only a few days ago that a distraught member in Essex has asked us to let everyone know that myxi is rife there at the moment. If you know of any outbreaks please let us know, or share them here.

Please don’t let your rabbits miss or be late for any of their vaccinations. Until the new vaccine becomes available later this year, keep to the dates your rabbits are due, annually for VHD and six-monthly for Myxomatosis.

A few weeks back we asked our Facebook followers for FAQs on Myxi and VHD, and this threw up some questions about hay too. Over the next few days we’ll be publishing one or two of your questions daily with answers from our Vet expert advisor Richard Saunders BSc (Hons) BVSc MSB CBiol DZooMed (Mammalian) MRCVS .

Thanks to everyone who took part and contributed, we hope that this is both interesting and useful:

Myxi – Q1)How effective is the new combined vaccine against myxo. Have heard of lots of cases of pseudo myxo in last 12 months on vaccinated rabbits. Will this still happen with combined vaccine, is it a new vaccine more appropriate to recent strains?

A1) Data sheet for it is now online.

In theory, this new vaccine should be better, and it has been tested against virulent strains.