Preventing the Spread of Myxomatosis and RVHD in Wild Rabbits: A Guide for Pet Owners and the Public

1. Introduction

This essay is intended to provide guidance to domestic rabbit owners and the rabbit-loving public, to prevent the further spread of myxomatosis and RVHD in wild rabbits. In the middle of 1952, a virus, mutant myxoma virus, was released into Australia in an attempt to solve the rabbit problem. In the UK in September 1953, mutant strains of myxomatosis were released into the wild rabbit population. The mortality associated with the two mutant myxoma viruses allowed a relatively few rabbits to eat a hole into the future, complete eradication was impossible - and that was the plan. It is arguable that the solution of the earlier rabbit infestations was largely down to the fact that infected sufferers had not long to spread the contagions in a wild population.

Two strains spread. Since then, natural selection has led to the development of yet another nonum mutant strain of myxoma virus, the progeny of cross between the two resistant strains. This nonum myxoma strain, which appeared in 2008, has been named NMAX163. There are now three strains of naturally occurring myxoma virus in Australia. Since May 2013, data for the spread of NMAX163 show the boundaries between the different strains are far from stable. RVHD, a different virus, is spreading with lethal results in wild rabbit populations in European countries such as the UK, Italy, France, and the Iberian Peninsula in Spain and Portugal. The bloody waxing and waning cycles of myxomatosis have thrived in an environment where rabbits are crowded together in close living quarters. In the first decade of the 2000s, a new fatal rabbit viral disease called Rabbit Viral Haemorrhagic Disease (RVHD) emerged in the UK. Unlike myxomatosis, it is often impossible to tell that a rabbit is unwell until it is found dead. RVHD is so contagious even shoe dirt can pass the virus. Whether a rabbit contracts a fatal strain of myxomatosis virus or RVHD cannot be predicted. Most die of RVHD, and slowly, when they are very ill. Most die of myxomatosis, and quickly, after a few days.

1.1. Overview of Myxomatosis and RVHD

Myxomatosis and Rabbit Viral Haemorrhagic Disease, commonly known as Myxo and RVHD, are both caused by viruses. Both diseases are seen in wild rabbits and hares and are prevalent in the populations of Great Britain. As wild rabbits make new burrows and dig up the earth, they can spread these viruses in the environment. The symptoms of Myxomatosis are swollen, runny eyes and swelling of the head and genitals, which can cause rabbits to be blind. Over time, Myxomatosis can also cause problems with a rabbit’s digestion. The symptoms of RVHD are fever, tiredness and sudden death, although rabbits are often found febrile after death. It is common for wild rabbits to have both Myxo and RVHD at the same time. This is an especially bad situation for rabbits that are not naturally immune to RVHD.

research has shown that over 80% of cases of Myxo and RVHD in pet rabbits are caused by direct contact with wild rabbits, their bodies or their urine. The chance of a pet rabbit getting both diseases at the same time is thought to be about 45% in areas where both viruses are found. Once wild rabbits within an area have these viruses, disease control is unlikely to be a long-term solution for pet rabbits unless vaccination becomes widespread. For example, RVHD and Myxo are both found in unmanaged rabbit populations on private and public land in the Canberra area of Great Britain. Wildlife managers are concentrating on vaccination of pet rabbits. If a vaccine can be given in sufficient time to ensure immunity, it is most useful in the different stages of managing the contacts that can occur between wild rabbits and pet rabbits.

1.2. Importance of Reporting and Handling Infected Wild Rabbits

The Weaver report shows that the presence of wild rabbits helps myxomatosis spread among wild rabbits. It also suggests springtime as the months when rabbit hemorrhagic disease (RHD) virus spreading is more likely to persist longer in the environment. The report concludes that farmers and pet rabbit owners then need to be aware of when the virus may be persisting longer in the environment to prevent their rabbits from getting infected. So it is important to report sightings of infected wild rabbits. Doing so can also help in our understanding of why outbreaks of the two viruses vary so much in rabbit populations.

We need the public to help in our disease surveillance. This means the public should be aware of disease symptoms and be responsible when a rabbit dies. If possible, the carcass should be either put in a double plastic bag and placed in the dustbin or buried at least 3 feet deep, or taken to a vet to have a post-mortem examination carried out. We need to know where wild rabbits are infected to help in vaccine selection and advise vaccinations of domestic rabbits. Basically, the same as pet rabbits should be managed such that they don't come into contact with wild rabbits or their environment. Generally, disease is picked up from contaminated boots and clothes rather than direct contact.

2. Symptoms of Myxomatosis and RVHD in Wild Rabbits

Myxomatosis

RVHD

2.1. Physical Symptoms

Physically, the symptoms of myxomatosis and RVHD can often be virtually indistinguishable from one another, but both conditions are unmistakable. They are well-known for causing a change in the rabbit's appearance, most commonly swelling or lumps on the face or around the eyelids which can make the rabbit look devilish or 'Chernobylish'. Additionally, swelling in the animal's genital region is not uncommon. Swellings on other areas of the body are also seen, such as on the base of the ears or other extremities. This can be the only sign of myxomatosis in some rabbits, earning the condition the moniker 'nodular myxomatosis'. Other symptoms include soiling near the rabbit's backside, due to the animal urinating uncontrollably or having diarrhea, or paralysis of the back legs. Less often, the rabbit may present other symptoms as well - lethargy, disinterest in food, difficulty breathing, ocular discharge (typically thick and green/yellow), or a nasal discharge which can be tinged with blood. Should any rabbit show any of these signs, they should be taken to a vet as a precaution.

RVHD is not truly an infectious disease, but it should be covered alongside myxomatosis due to it often being found in circumstances alongside myxo. There are symptoms seen in some rabbits that differ from the usual image of the condition - 'stomach' RVHD results in a rapidly ill rabbit that refuses food and has runny stools littering both itself and the hutch. Most rabbits with either kind of RVHD will, however, die without showing any symptoms whatsoever. As before, any rabbit showing any suspicious signs should have the vet called as a swift and automatic response. Preventing the spread of myxomatosis and RVHD in wild rabbits - a guide for pet owners and the public.

2.2. Behavioral Symptoms

Myxomatosis and RVHD1/2 can be rapidly fatal in rabbits, and they are often hard to identify by other means. Nonetheless, visible symptoms can occur early on and, beyond preventing the spread of infection, they can help in identifying and monitoring outbreaks, and in providing appropriate supportive care. The following are possible symptoms and behaviors that owners should be aware of, and report to the relevant organizations if observed. However, it should be emphasized that a rabbit showing any unusual changes in behavior, activity level, or physical condition should be taken to a veterinarian without delay.

Different rabbits, or rabbits at different stages of the disease, may present differently. Fear typically increases at the onset of the fever. The animal may appear nervous, moving away, or hopping, running too far from usual rather than crouching, slinking, or hiding. Fear responses include activation or "red eye" where they show the whites of their eyes or may not blink. Aggression can be shown by pounding the feet, charging, or biting. Rabbits are not usually vocal animals, but the pain accompanied with the fever, especially in the initial stage, can cause the rabbit to emit a squeak, especially during handling. Many of these signs are shared with feeling very unwell from other reasons, so the "trusting to come in" part is key.

3. Reporting and Safely Handling Infected Wild Rabbits

If you observe an infected wild rabbit or a wild rabbit that shows signs of disease, please report it to us or Defra straight away. If you are taking your pet rabbit to a vet, please inform your vet before your visit so they can take appropriate precautions. Reducing exposure is important not only for local authorities and landowners, who may not want human or wildlife traffic coming onto their land to search for rabbits, but also to reduce the risk of infection spreading from affected areas to unaffected areas. Rabbit owners should prevent contact between their domestic rabbits and all wild rabbits, either dead or alive, where possible.

If you find a wild rabbit that you believe is infected (because it has one of the symptoms listed above), reporting your find to the relevant authorities will ensure that someone who can check the rabbit and remove it will visit the area. Wild adult rabbits can be humanely killed by giving a sharp blow to the back of their legs using a long, heavy implement such as a stick or shovel. This should crush the spinal cord and ensure that the animal is not left in pain and distress. The carcass can then be placed in a sealed plastic bag and disposed of in a household waste bin. Protective gloves should be worn when handling the carcass of any dead rabbit or a pet rabbit that has recently been put to sleep, and hands must be washed afterwards. Full advice on how to safely pick up and transport dead rabbits to the Animal and Plant Health Agency (APHA) or Centre for Ecology & Hydrology (CEH) is provided in the United Kingdom Specific Plan for emergency response to RHDV2 (which also applies to myxomatosis) in rabbits. In middle to high-density urban areas, contact your local authority's Street Scene or Pest Control department for assistance.

3.1. How to Report Suspected Cases

If you see wild rabbits acting ill, tame rabbits with them should be brought indoors. They should not be moved or released into the wild, as they may be diseased. There are several options for reporting suspected cases of myxomatosis and RVHD, as follows.

1. By Email: To the Australian Government Department of Agriculture, Water and the Environment. Report all sick rabbits promptly using the Government’s online reporting form: (also known as the AUSVET report) or contact their Emergency Animal Disease Watch Hotline: 1800 675 888.

2. By Phone: Vets are obliged to report certain diseases but may not always make the most needed reports in a reasonable time frame. Reporting specifically when you see cases in wild rabbits may be more effective than just trusting that they have. Calls made to the South Australian and Victorian RVHD and Myxomatosis hotlines would travel by reports to the government, but ring between 9–5 week days: Myxomatosis and RHD in South Australia – Call PIRSA’s Exotic Animal Disease Hotline on 1800 675 673. RHD in Victoria – Call Agriculture Victoria on 136 186.

Wildlife organisations fighting myxomatosis and RVHD welcome reports of dead wild rabbits, and with their benefit from the increased awareness, they should be more likely to use the information to catch and test sick animals. In South Australia, you can report ill or dead wild rabbits using their online report form:

For any additional advice or support if you find wild rabbits with a suspected disease, you can contact the Animal Planning and Response Team at PIRSA on (08) 8207 7914.

3.2. Safety Precautions for Handling Infected Rabbits

One of the most common ways that viruses are spread is by humans touching infected rabbits and then carrying the virus to uninfected rabbits. The people who sit with the rabbits are at significant risk. If you can't help or don't help with these precautions, there are risks to all. You won't spread the viruses to your rabbits' long-term population, but while you have sick rabbits, there is a real risk that: 1. They can transfer to their family's dogs, cats, and fowl. 2. They can be transferred to citizen rabbits via the Myxiatosic flea that occurs naturally in the United Kingdom and other countries, possibly causing a new epidemic. We all know that this seems rather dismal. Exceptions can and do occur, as we shall note below when we discuss vaccines. And in terms of individual rabbits surviving the virus, the chances are worryingly high! If a rabbit is handled properly and has round-the-clock access to excellent medical treatment and pet care, it has a good chance of surviving Myxomatosis and RVHD. However, from a public health standpoint, this has the potential to exponentially expand the pool of patients that, theoretically at least, may isolate contagious viruses. And so, with these frightening ideas behind us, let's begin!

First and foremost, the most important thing anyone who comes close to the affected rabbit must do is to wear rubber/latex gloves, and to change and wash hands thoroughly with hot soapy water afterwards. This is to avoid spreading Myxomatosis directly from hands to other rabbits, or indirectly through their food and environment. Most of your contact with the rabbits must be direct handling through the cage bars, without gaining access to their bedding/materials or any of their food/vegetables. During a visit, you will be observed by someone whose clothes have been sprayed with disinfectant, to further reduce the possibility of Myxomatosis being introduced into the rabbit's environment. Provided you follow these rules, the only danger you will pose to your rabbits is upon arrival and leaving, when the person wearing the disinfected clothing will escort you to the rabbit room. Remember - you will not harm your rabbits by complying with these rules! It is newly inflicted spores of the virus that pose a danger to other rabbits, not the rabbit itself!

4. Preventive Measures for Protecting Pet Rabbits and Hares

Provided that the myxomatosis and RVHD viruses are maintained in wild rabbit populations, some pet rabbits are, in effect, vaccinated by exposure to the virus. Myxomatosis virus is spread readily between rabbits, so if contact between pet rabbits and rabbits in the wild can be avoided, vaccination of pet rabbits can be relatively effective in preventing pet rabbits from getting the disease. Pet owners and veterinarians can benefit from keeping pouch vesicles and sending them to the laboratory, which will then confirm the infection. Biosecurity, however, is the heart of prevention. You cannot simply chase hares or wild rabbits away from your house and hope for the best, as some diseases can be carried by birds or insects.

With that in mind, the Australian Veterinary Association provides a list of general biosecurity measures advised for all pet rabbit and hare owners. First, the AVA advises pet owners and pet businesses to keep all pets up to date with their vaccinations. This helps to lower the number of susceptible animals that could come into contact with the disease. The AVA recommends all pet rabbits be vaccinated with an inactivated vaccination against myxomatosis, RVHD1, and RVHD2. If a pet is deliberately coming into contact with wild rabbits or hares, the owner should be aware that the pet is a dead-end host and needs to be vaccinated using the same vaccine that is used in wild rabbit vaccine distributions. And although it is well known to eat rabbit food, don't let your pet rabbit or pet hare eat grass or hay that has been mowed by a contractor who also conducts fumigation, as the pellets used can pose a risk to unprotected pet rabbits and hares. Furthermore, separate outdoor cages are recommended for sick pets, shortsighted pets, or pets with low immune systems. Also, place a damp cloth over the gaps in the cage as a precaution and do not work over the cage or be exposed to the urine, feces, or bedding of pets. Always wash hands before and after interacting and disinfect food and water bowls at least daily.

4.1. Vaccination and Health Monitoring

At present, standard vaccines used to protect pet rabbits from Rabbit Viral Haemorrhagic Disease (RVHD) contain strains of both RVHD type 1 and type 2. These vaccines have not undergone rigorous testing for their ability to protect rabbits from the new variant strains, and there has been little, if any, testing of some of the new vaccines available in the UK for their ability to protect rabbits against the original mild strains. The choice of which vaccine is to be used is therefore currently advised to be based upon the risk association with the two new variant strains and the strain available. Vaccination protocols always involve an initial primary course of vaccinations followed by regular 'boosters'. Until further formulation testing has been completed, it is advised that the basic vaccines against Myxomatosis and RVHD1 and 2 are used.

All vaccines are licensed to be administered to healthy rabbits over 5 weeks of age, with an initial course of two vaccinations to be given at two-week intervals. These should first be given after 5 weeks old, with the second vaccination at or after 7 weeks of age. Ideally, if the vaccination programme is started late in the first year, the vaccine should be given at 4-weekly intervals to start, as it used to be advised. Provided no vaccine is given on the same day as another vaccine, most animals can safely have long-life hepatitis vaccines with a four-week interval from Myxo-RHD vaccinations. VHD vaccines are killed viruses and cannot spread.

4.2. Biosecurity Measures

Biosecurity is a set of practices undertaken to prevent the introduction and spread of disease. There are several biosecurity measures that you can adopt which will help you prevent your pet rabbits from becoming infected and inadvertently introducing these diseases into wild populations. As an added bonus, following these practices will help you to protect your rabbits against many other infectious diseases.

A strong fence that keeps wild rabbits out of your rabbit's grass runs is the single most effective method of protecting your rabbits from disease. Fencing will also help to keep your rabbit safe from traffic, predation, and loss. Hang strips of flyscreen across gates and doorways to grass runs to prevent insects such as mosquitoes, midges, bush flies, stable flies, blowflies, and flesh flies from entering and coming into contact with your rabbits. Use flyscreens as well on windows that will be left open. Grow a screen of thick, tall, and dense hedges of shrubs around the rabbit hutches to provide a physical barrier between your rabbits and wild rabbits from surrounding areas. Cutting grass around rabbit hutches and runs helps reduce piles of grass that wild rabbits can use as hiding places concerning fences, which make mousetraps less effective. It further reduces flies and insects and the dangers associated with them.

Biosecurity measures are associated with the natural behavior of rabbits, and mowed grass areas will not prevent rabbits from grazing or lounging around on all fours for short periods. Use two layers of stainless steel heavy-duty fly wire to cover the outside with expandable cladding covering any cement sheeting so that the join is not visible. Also, ensure this is secure as cats can chew their way through wire. Use strong internally coated stainless steel mesh doors as well for added protection. Keep rabbits inside after nightfall. Mosquitoes and midges that transmit Myxomatosis and RVHD are most likely to be flying from dusk through to dawn.

5. Raising Awareness through Social Media

Pet owners and animal lovers are often active on social media platforms. Several social media groups are also dedicated to this topic, and these groups consist of rabbit rescue communities, pet rabbit owners, rabbit breeders, veterinarians who treat rabbits, rabbit patients, rabbit dying process communities, and individuals who regularly participate. Here, we propose four guidelines that social media can follow to raise awareness about myxomatosis and RVHD and save wild rabbits from these dreadful diseases. It is important to bear in mind that any social media campaign should be sensitive to the points laid out in 1.1.

While the messaging can be in the form of memes, stories, infographics, etc., playing to each platform and its algorithms, every post should prompt action and the call to action for each post should be clear. Possible platforms to utilize include but are not limited to what is and isn't being done in Australia, posts on identifying myxo and RVHD, and posts promoting how to reduce the risk of wild rabbits contracting myxo and RVHD. It may be beneficial to partner with well-known animal charities who share educational content or to try and respond and engage on social media posts from relevant high-following accounts. These tips should be updated and shared again each year to optimize the fresh, targeted messages.

5.1. Effective Messaging Strategies

Crafting effective public messages to engage the public will be essential for preventing the spread of myxomatosis and RVHD. Messaging should be broadly accessible so that it reaches pet owners as well as the general public. Target audience testing should be used to "field test" exhibition materials with the local community, looking for signs of confusion or resistance.

For the most part, messaging should avoid technical, scientific language. People are invested when messages reference pets, animal suffering, and "common sense" values like "veterinary care for all individuals, wild or domestic." Talking with people in approximately 100 vehicles at Silver Crest (2/7/21) confirmed several public messaging needs: language should be basic, in accord with "pet owner and family" interest; literature should be distributed to all; prior to that event should be signage, posters in the community via partners; and widely shared on social media. Messaging should be clear, to the point, and mobile. Finally, messaging must be adaptable, that is, it cannot expect the public to be in one place at one time (figuratively, like reading a newspaper or even participating in any one local activity, at any one evening or weekend event, or having the words in messages read aloud on the radio), because there is not a singular conduit that reaches everyone in an area. For example, messages should circulate throughout a wide berth of radio stations, print media, social media, local events via booths/handouts, posters, and partner collaborations so any one adult might see and hear the messages at multiple points.

5.2. Utilizing Platforms for Maximum Reach

5.2. Utilizing platforms for maximum reach: Further practical and logistical aspects arranged prior to the development of assets include the size and location of the audience. This will dictate how much resources are or can be invested in the development of assets and their distribution and may also be relevant to some digital platforms where different kinds of targeting can be achieved. It is useful to have a low barrier to entry for engagement. Facebook can be helpful for gaining some feedback from the public and engage with them through polls and comments, but alone is not a great tool for participative action. Twitter is known for its ability to spread a message quickly through retweets, and is more interactive than Facebook. Twitter can also be used as a feedback tool to gauge the public's uptake of and understanding the messaging. Many social media users have multiple accounts across various platforms, however this may not be true for all demographics or groups of professionals.

5.2.1. Facebook. A Facebook event page gives you the opportunity to collect a group of like-minded people who you can then invite to an event. A Facebook page can be used to create and share posts, with the ability to schedule when a post should go live, and also conduct live video feeds. Obviously posting updates to both the page and the event will require a reboot of the original asset. Any videos can be saved and posted separately after the asset has been rebranded. Polls can be created to gather info such as who has supported the campaign, etc. It is also a good place to test out short status updates at a glance. Polls could be both serious (i.e., will you talk to your vet about vaccination), to a more light-hearted (i.e., what is your rabbit's favorite treat). You are much likely to connect with your audience by having conversations to simulate other conversations within their peer groups. All page posts that you mention and state a specific Facebook username/identity can send an automatic notification to the user for that page which alerts the person they have been tagged or mentioned in a post. If sent by the page. Also, those pages you have liked and where you have tagged/mentioned them in a post, the user will automatically receive a notification. The majority of people who use Facebook use it passively, i.e., they observe more than they engage. With a Facebook page, you can get live data insights on how many people are engaged and what posts are reaching the most people so that others can be boosted to make sure your reached numbers are better.