May 30, 2016
Updated Dec 2016.
RVHD1 and RVHD2
This article will provide a concise overview of Rabbit Hemorrhagic Viral Disease, its characteristics, locations, testing methods and some of the preventative steps that can be taken.
Rabbit Viral Haemorrhagic Disease 1 is a type of Calicivirus, has been in Europe for many decades or even centuries and affects both wild and domestic rabbits. There are a few different pathogenic strains of the virus but until recently, RVHD1 was thought to be the only type in the UK.
RVHD2 differs in a few key ways as it is unaffected by age and has a longer illness phase with different clinical symptoms. It is also thought to have a lower mortality rate. Little research has been done on RVHD2 and it is highly likely that cases are under reported.
Both viruses are potentially very easily spread and can live in the environment for a long time (RVHD2 up to 200 days in laboratory conditions) Insects, wildlife and scavengers can spread it as well as direct contact with an infected rabbit. Fomites such as bedding, wild plants, shoes and clothing can also carry the virus to new areas. It is currently unknown if biting insects can spread RVHD2.
Due to it being so easily transported, the spread of RVHD can be very quick and strict biosecurity is recommended as well as vaccination.
The current UK vaccine, Nobivac Myxo-RHD offers protection against RVHD1 but is unlikely to offer any for RVHD2 as this virus is antigenically and genetically different from RVHD1. It is recommended that a second vaccination be given to cover RVHD2 and there are a few options:
- Eravac has been licensed in the UK for use in ‘fattening’ rabbits. This is an oil based drug with no research showing the possible long term effects and there is currently no recommended vaccination schedule.
- Cunivak RHD is currently out of stock and Cunipravac can be ordered via a special import certificate however it is only available in large multi dose bottles.
- Filavac RHD K C+V is available to order from most UK wholesalers and is administered annually or 6 monthly (if considered to be a high risk patient or area). It is vital that the rabbits are still vaccinated with the Nobivac Myxo-RHD as the Filavac vaccine does not give any protection against myxomatosis, however standard immunology advice is to leave at least a 2 week gap between the different vaccinations.
It is important to research all options and discuss with your vet / client. The safety and efficacy of using any other vaccine alongside the Nobivac Myxo RHD has not been studied.
It is not recommended to carry out en-mass vaccination clinics as this could potentially increase the risk of disease spread due to the way RVHD is transmitted.
Testing and Reporting
Its important to consider RVHD2 as a differential diagnosis when dealing with a sick rabbit that doesnt seem to respond to treatment and no obvious reason for the illness is found. PCR testing is now available for live rabbits via the Batt Laboratories in Coventry. For sudden deaths, post mortem liver samples can also be sent here or to the Moredun Research Institute.
Wherever possible, please send samples to either laboratory via the methods outlined on their websites. Please also consider reporting all suspicious deaths to the Rabbit Welfare Association and Fund as their Veterinary Advisor is monitoring the spread of this disease.
Good husbandry is paramount and sick rabbits should be barrier nursed. Enhanced cleaning, disinfection and quarantine protocols can be implemented in practice and with owners. Anigene HLD4V is a veterinary grade product that is believed to be effective against RVHD when used at a concentration of 1:50 for soiled conditions.
It is vital to be aware of the risks associated with attending events such as rabbit shows, petting zoos and even rescues. Environmental insect controls should also be in place as it is still unknown if RVHD2 can be spread via insects. Care should also be taken when considering feeding handpicked wild plants.
Keeping Up To Date
There is a great group on Facebook
where people can report suspected and confirmed cases of RVHD1 & RVHD2. This links to a UK map and it also holds a wealth of information and support – I recommend everyone to join.
You can also visit the Rabbit Welfare Association’s website as they will always have the most up to date and factually correct info.
Lastly, Rabbit Specialist Vet Francis Harcourt Brown (retired) has information about the disease on her website.
Be wary of other reports and anecdotal stories doing the rounds as they may not be factually accurate. Also, please contact your own vet asap so they are fully aware of the new RVHD2 strain and that they are stocking and advertising the new vaccine to help fight this. We need owners to insist all their vets order in the vaccine to get as many rabbits as possible protected against this fatal disease.
Please know how to keep your rabbits safe and spread the word!
January 12, 2016
RVHD and Myxomatosis are diseases found throughout the UK and can be fatal to un-vaccinated rabbits. Both outdoor AND indoor rabbits are at risk. RVHD in particular is highly infectious and contagious. It is an air borne virus that can be spread by direct and indirect contact with infected rabbits, food bowls, hutches and even the soles of your shoes. For example – if you, your dog or cat has walked on ground where a VHD infected rabbit has been, you can carry it on your clothes or shoes, your other pets can carry it on fur or feet. The virus can survive in the environment for a long time and can survive cold temperatures far better than you might expect.
“As you may know, over the past year there has been an increasing concern regarding RVHD “new variant 2” becoming a cause of deaths in several outbreaks in the UK. Whilst it has been noted in the UK in research papers (Westcott and Choudhury) for at least 2 years, it has clearly become a significant clinical entity in the past few months.
We (RWAF) have now successfully established an SIC (Special Import Certificate) for a suitable EU member state vaccine, Cunivak RHD, and placed an order for a small number of vaccines to establish an ordering system into the UK.
Vets can order their own supplies from VMD. If they require any further information, they should contact the RWAF at [email protected] and we will pass on any veterinary queries to our vet, Mr Saunders, but they should be aware that he may be dealing with a high volume of email. A more detailed explanation of the above should be available in Vet Times and Vet Record soon.”
What This Means For Owners.
Firstly – please note that NO emails from owners about this topic will be passed to Dr Saunders. he will be dealing with Vet emails only due to the high volume of contact.
So for owners – this means you will need to ask your vets to order in the new vaccine which will take a few weeks for them to sort out. The new Cunivak vaccine is NOT a replacement for the current combo vaccine and will need to be given AS WELL AS the Nobivak
one. Its important to note that these vaccines CANNOT be given at the same time and need at least a 2 week gap between them.
In total, your rabbit will now require 2 vaccinations (comprising of 3 injections) per year:
1) Nobivak combo – Just one injection covers them for myxomatosis and RHVD1.
2) Cunivak RHVD – 2 injections 3 weeks apart. This covers them against RHVD2.
You need to leave AT LEAST 2 weeks gap between the different types of vaccines. If you can manage to schedule it so that there is a gap of 4-6 months between vaccines then this would mean your rabbit would have a veterinary health check up approx every 6 months. BUT you don’t HAVE to work to this schedule, just make sure there is at least 2 weeks between vaccines.
Please contact your vets and ask them to start the process of ordering in the new Cunivak RHD vaccine. Most vets will not be aware that they can do this as the information has only just been released. But the quicker you contact them, the quicker they can get up to speed and get the vaccines in stock. If your vets are unsure, please advise them to email [email protected]
for more info. As per the RWAF first alert above, this information will be released in veterinary publications in the coming weeks.
If your rabbit is vaccinated with the Nobivac combi vaccine AND the Cunivak vaccine, they will have been vaccinated against Myxo, RHVD1 and RHVD2. As always, no vaccination is 100% effective and it does not mean your pet will not contract the disease. However, it does mean they have a chance to be treated and survive these normally fatal illnesses.
June 19, 2014
Flies are not just a buzzy pest….they can cause serious damage to your bunnies!
RWAF Flystrike Poster
Fly strike is also known as Myiasis and is defined as “the presence of larvae of dipterous flies in tissues and organs of the living animal, and the tissue destruction and disorders resulting there from” (Boden, 2001). All very scientific…but basically, flies can lay eggs on bunnies and these quickly hatch out into maggots which eat the bunnies skin and organs 🙁
Initially, rabbits can hide fly strike quite well as the eggs and maggots are usually buried deep in the fur. “Bluebottles (Calliphora) and greenbottles (Lucilla) are attracted to soiled fur or infected skin to lay their eggs” (Harcourt Brown, 2002). The most common site for this to happen is around the rabbit’s anus and scent glands. A rabbit that is overweight, unwell or suffers from joint problems will struggle to keep this area clean. This can then lead to the fur being matted with urine and faeces, which attracts the flies. The eggs that are laid will hatch into larvae (maggots) in approximately 12 hours and will start feeding on external debris. Once this has been consumed, the maggots will continue to eat sound skin and tissue, often tunnelling under the skin layers. Aberrant migration brings the maggots deep under the rabbit’s skin, infiltrating vital organs and can even occlude the rabbit’s airway. This is very uncomfortable for the rabbit and will progressively get more painful as the condition progresses. Initially the rabbit will be very restless, however as time goes on it will become unwell, inappetent and lethargic.
The combination of the sore skin and the maggots creates a very pungent ammonia smell. This is because the maggots release proteolytic enzymes into the tissues to cause cell death and decomposition. These toxins can cause serious shock, septicaemia and if left untreated, will often be fatal.
For treatment to be successful, the rabbit needs to be seen by a Veterinarian as soon as possible. Depending on the severity of the case, the rabbit may have to be hospitalised for intensive therapy and monitoring for a few days. Rapid removal of the eggs and maggots is imperative to stop any further damage. This can be done by shaving the fur off the affected areas and then carefully using forceps to remove the contamination. This can be very time consuming and will need to be repeated a few times to ensure all of the eggs and maggots have been removed. The skin needs to be flushed and cleaned with a sterile saline solution and an antiseptic solution (such as povodine-iodine) and any wounds will need flushing and exploring to make sure that they are also clear of contamination. Non-steroidal pain relief and fluid therapy are vital to help the rabbit combat shock. Not all patients will be well enough to endure a sedation or anaesthetic at this point so care needs to be taken and close monitoring performed. The rabbit will need to be dried well and placed in a clean, warm and quiet area. Sometimes the use of topical creams like Dermasol (by Pfizer) is advised as it promotes healing of areas impaired by the presence of necrotic tissue because it activates the sloughing of devitalised tissue. Intensive nursing will also be vital to the success of the treatment. The rabbit will need regular syringe feeding, medicating and cleaning along with trying to keep its environment warm and as stress free as possible. F10 wound spray with insecticide can be used on the area – helping the wound and protecting from further fly problems too. This can be used daily and is good for disabled rabbits that need daily clean ups (thus washing off any Rearguard etc).
If there is a heavy maggot burden, injections of Ivermectin can be given to kill the maggots but the patient must be very closely monitored as the dying larvae excrete toxins that can be fatal. The final treatment option is surgery for when the maggots have migrated far under the skin. However, such a heavy burden does not have a good prognosis and often euthanasia is the kindest option for severe cases.
WARNING! F10 wound spray is TOXIC to cats. Do NOT use on cats or in households where cats and rabbits have direct contact.
As always, prevention is better than cure and there are a number of things that owners can do to help reduce the risks. Owner awareness of fly strike is vital and they must be able to recognize the signs and know that this is an emergency that needs Veterinary attention as soon as possible.
In general, it is very important that the rabbit is kept in good physical condition. This means that it is fed a balanced diet consisting mainly of good quality hays with a small amount of commercial rabbit pellet and fresh vegetables and herbs. By feeding the correct diet, it reduces the risk of the rabbit becoming overweight and also reduces the risk of over producing caecotrophs which get stuck around the anus. Rabbits that are very young, very old or have health problems such as dental, gut or paralysis issues are more susceptible to fly strike.
Next, it is important that the rabbit is kept in clean, spacious living conditions. Any build up of urine or faeces will attract flies. The rabbit should also have plenty of space to move around and exercise away from its toileting area and uneaten fresh vegetables etc should be removed daily. If housed outdoors, mosquito netting can be used over the hutch and run areas to help reduce the amount of flies that can enter the area. It can also be attached to windows / door areas too. Sticky fly paper can be used outside the hutch but never in an area that the rabbit has access to as it can stick to them and cause terrible damage. If the rabbit is housed indoors, an electric insect killer can be used in the same room as the rabbit is housed and net curtains can be used in the windows to reduce the amount of flies entering the room.
Lastly, a topical treatment can be applied to the rabbit to help prevent fly strike. F10 wound spray with insecticide and Rearguard are examples of these topical treatments. F10 wound spray needs to be applied weekly to the rump and genital area. It is TOXIC to cats so don’t use on cats or in households where the cats and rabbits interact.
The main ingredient in Rearguard is Cyromazine (an insect growth regulator). It is recommended by many Veterinary practices and is widely available in pet shops and online. It should be applied at the start of summer before any flies are seen and gives approximately 8-10 weeks of protection. This product does not repel flies or kill maggots but works by preventing any eggs laid on the rabbit from hatching into maggots. Rearguard can also be applied on rabbits that have been successfully treated for fly strike to help prevent re-occurrence.
The bottle comes with a sponge applicator but I find this often has a sharp spike in the middle. So I wear a pair of disposable latex / nylon gloves and apply the liquid to my hands. I then rub this into the rabbits fur from the middle of the back to the tail and the same on the underside. Its important to get the fur quite wet and apply well around the back legs and genitals.
DO NOT APPLY TO SORE OR BROKEN SKIN.
The bottle says to use the whole bottle per rabbit but I have found that you can often get 2-3 applications out of one bottle for small / medium bunnies. As long as the target area is covered and the fur quite wet then this should be fine.
Re-apply every 8-10 weeks.
See here for more info (WARNING! some contain graphic images):
Rabbit Welfare Association and Fund
House Rabbit Society