Rabbit Vaccinations – Are they necessary?

In the UK we currently recommend vaccinating rabbits against two diseases; myxomatosis and rabbit viral haemorrhagic disease (RHD). To understand why vaccinations are so important we need to know what they are protecting our rabbits against.

Myxomatosis

What is it?
Myxomatosis is a disease caused by the myxoma virus and has been present in the UK since 1953. There are different strains of the virus which can result in different forms of the disease some more severe than others (see below). In unprotected rabbits, the disease is usually fatal and so prevention is strongly recommended.

What are the symptoms?
There are two types of myxomatosis, nodular (lumpy) and oedematous (swollen) but the latter is the most common and the most lethal. Symptoms begin between 4-10 days after infection;

 

Oedematous (swollen) Type Nodular (lumpy) Type
  • Swelling around the eyes, mouth, bottom and/or genitals
  • Decreased appetite
  • Dull behaviour
  • Light sensitivity
  • Secondary infections (eyes, nose, lungs)
  • Weight loss
  • Difficulty breathing (end stage) and death
  • Lumps in and/or under the skin
  • Lumps become ulcerated (open wound) but can heal over
  • Secondary infections

It is possible for rabbits to get a mixed form with symptoms from both types of the disease which may be milder. The oedematous form acts quickly and after around 1-2 weeks of symptoms rabbits will die from starvation and difficulty breathing.


How do rabbits get it?

Rabbits can become infected with the virus from direct contact with other infected rabbits but also from being bitten by blood sucking-insects with the virus. These insects become carriers when they feed on infected rabbits but don’t become ill themselves, allowing them to move on and feed on another rabbit passing on the infection. Any blood-sucking insect can be a carrier but fleas and mosquitoes are the most common and because mosquitoes can fly long distances, they also help spread the disease to new areas.

Can you treat it?
Treatment of the oedematous form is usually hopeless, particularly if the rabbit is already having difficulty eating or breathing. Due to this our vets sadly will most likely recommend euthanasia to stop the rabbit from suffering. Rabbits with a mixed form of the disease may be able to survive with supportive care if the disease is mild. Supportive treatment is typically aimed at maintaining adequate nutrition and alleviating other symptoms while the immune system clears the virus. This may include;

  • Fluid therapy
  • Syringe feeding
  • Antibiotics if there is a secondary infection
  • Anti-inflammatories for the swelling
  • Active warming

How can I prevent it?
Rabbits can be vaccinated against myxomatosis from 5 weeks old. This vaccine should be repeated every year to maintain adequate protection. Rabbits in high-density populations such as those used for breeding can be vaccinated every 6 months. Vaccinated rabbits can still become infected with the virus but the symptoms are normally very mild and treatable.

You can reduce the risk of infection further by ensuring your rabbit does not have contact with wild rabbits which may be infected, or eat food from areas where wild rabbits live. Protect your rabbits from insects that may carry the disease by using insect screens and flea prevention spot-ons. If you’re introducing a new rabbit, quarantine it for at least a fortnight to ensure it is not infected before exposing it to your current rabbit/s.

Rabbit Haemorrhagic Disease (RHD)

What is it?
RHD is a deadly disease caused by a calicivirus which can be transmitted both directly and indirectly. The RHD virus is currently divided into subtypes including RHD1 and RHD2. The virus has been present in Europe since 1988 but a recent outbreak of RHD2 in the UK started in 2013 and has caused a large number of rabbit deaths.

What are the symptoms?
Sadly, one of the most common symptoms of RHD is sudden death, with many owners believing their rabbit died of “fright” or a heart attack. External symptoms are not always seen and so many rabbits dying from RHD are not known, meaning the disease is likely more widespread than we think. The disease acts so quickly (within 1-3 days of infection) that rabbits can look completely normal the day before. Possible symptoms include;

  • Sudden death
  • Bleeding from the nose/mouth/bottom
  • Lethargy
  • Decreased appetite
  • Difficulty breathing
  • Fever (early)
  • Seizures
  • Vocalising
  • Collapse

A mild form of the disease does exist but this is very uncommon and those rabbits are normally just generally unwell with non-specific symptoms which often mean we do not recognise they have RHD.

How do rabbits get it?
The virus can survive in the environment for many months, especially when it’s cold, allowing it to cause disease outbreaks year after year. RHD can infect rabbits directly through bodily fluids such as faeces/urine/saliva and mating as well as indirectly by contaminated objects such as clothing/cages/bedding/food/humans as well as insects, birds and rodents carrying the disease. There is even suspicion the virus can be carried on the wind. Blood-sucking insects such as mosquitoes and fleas can cause the virus to spread quickly and over considerable distances.

Can you treat it?
RHD is usually fatal and cannot be treated so vaccinating your rabbit is strongly recommended to prevent them from getting it. We may be able to provide some supportive care to infected rabbits but normally our vets will recommend euthanasia to alleviate suffering. Rabbits known, or suspected, of being infected should be isolated from all other rabbits and strict hygiene protocols used to prevent the virus from being transported elsewhere. All equipment and housing should be thoroughly disinfected and cleaned.

How can I prevent it?
Vaccines exist in the UK for both the RHD1 and RHD2 types of the virus. As there is no way of predicting when a rabbit may become infected with RHD, vaccination to protect every rabbit is the best-recommended action. Vaccines can be given from 4-5 weeks old and then a booster every 6-12 months is advised as the reported duration of immunity is 9 months-1 year. In the UK the RHD1 vaccine can be given at the same time as the myxomatosis vaccine, then the RHD2 vaccine is licensed to be given a minimum of two weeks later.

Where possible you can try and limit exposure of your rabbit to RHD by quarantining any new rabbits, using insect screens and flea spot-ons, and avoiding contact with wild birds and rodents. General hygiene is also important; we advise that all objects (e.g. water bottles, bowls, cleaning equipment) are cleaned and disinfected regularly as well as your rabbit’s housing. Bedding should be changed regularly and along with hay, should be sourced from a supplier where it has been grown with no known infected wild rabbits.

Conclusion: Is vaccination necessary?
There has been a lot of concern in recent years about over-vaccinating our pets and whether annual vaccination is needed. Given the large number of deaths reported for both diseases and the ability for these diseases to spread to different geographical locations we feel vaccination is essential to protect all rabbits as there are no “safe areas”. In rabbits, a single vaccine has only been shown to provide protection for 9-12 months when vaccinated rabbits are challenged with RHD2, which is why we recommend that you give your rabbits annual vaccinations. Additionally, one study showed that cross-immunity between RHD1 and RHD2 was minimal and so both vaccines are needed to ensure adequate protection.