Protecting your Rabbits Against Fatal Disease
Our rabbits are all at risk of two potentially fatal diseases. Because of our very large wild population it is impossible to eliminate the risk of transmission in any way other than by vaccinating all of our pet rabbits, including house rabbits. Thankfully there are vaccinations to provide protection against these two diseases – Rabbit haemorrhagic disease and Myxomatosis.
Myxomatosis is very common in wild rabbits and unfortunately invariably proves fatal. Myxomatosis causes swelling of the eyelids, skin around the ears, lips and genitals. Treatment is supportive, but unfortunately most rabbits will die following infection, and the disease process can be long, distressing and painful, so euthanasia is often the kindest option.
Myxomatosis is spread by direct contact and via flying or biting insects that move from an infected rabbit to a healthy one.
Vaccination against myxomatosis is very effective and requires a yearly booster. We can vaccinate rabbits from 5 weeks old and it takes 3 weeks for it to become effective. In rare cases it is possible to rabbits to contract a milder form of myxomatosis if they are vaccinated, however vaccinated rabbits carry a very good prognosis and will mostly make a full recovery.
Rabbit Haemorrhagic disease (RHD) is a highly lethal disease in rabbits, and unfortunately the incidence and therefore the risk of infection has increased dramatically over the last few years.
There are two variants of RHD: RHD 1 used to be the only variant seen in the UK, however since 2013 a new strain of RHD (RHD2) has come over to the UK from mainland Europe and this new strain is more virulent and now appears to be the main cause of RHD related deaths in rabbits in the UK. RHD2 is rife in the wild rabbit and hare population and unfortunately whilst young rabbits exposed to RHD1 could develop immunity to this strain, age immunity doesn’t occur with RHD2 and so young rabbits can also be affected and be killed by this disease.
RHD has a very short incubation time, meaning that clinical signs may develop within 1-4 days for RHD1 and 3-9 days for RHD2 from exposure. The virus replicates within many tissues including the lungs, liver and spleen and causes clotting failure leading to fatal haemorrhage or liver failure. More often than not, rabbits affected by RHD are found suddenly dead, having been eating and behaving normally previously. Sometimes rabbits may develop lethargy, a fever, and show an increased respiratory rate before dying within 12 hours. It is thought to be possible that rabbits that are exposed to virus and survive could develop some degree of immunity; however it is possible that they may develop liver disease over time.
Diagnosis of RHD is by post mortem examination and confirmation by testing samples of the liver to identify the virus. Samples however need to be taken as soon as possible after death to give the best chance of a diagnosis. Most of the time a presumptive diagnosis is made based on the clinical signs.
RHD is difficult to kill and can survive harsh environmental conditions, it can survive temperatures up to 50◦C and is not inactivated by freezing, therefore it can survive in the environment for many months.
Carcasses of dead rabbits can be a source of infection and it can be spread by scavengers and insects (including flies), hay and vegetables from contaminated pasture could also be a source of infection. Likewise, we as owners could walk RHD into our homes after walking where infected wild rabbits may have been. With this in mind – all pet rabbits are at risk of this disease – whether they are kept indoors or apart from other rabbits.
In the unfortunate case of an outbreak, the most responsible course of action is to limit movement of all rabbits to prevent spread; any surviving rabbits will have been exposed by the time a single death has occurred. The time frame to limit movement is difficult to predict, but guidelines suggest waiting 4 months before moving rabbits or considering introducing new rabbits to survivors should be sufficient. Virucidal disinfectant is required to clean the environment, often replacing housing or keeping empty for 4 months + after an outbreak would be recommended.
In order to protect our pet rabbits against RHD 1 and 2 we need to vaccinate them. The vaccination that we use to vaccinate against covers rabbits for RHD1 only, so all rabbits require a second vaccination to give immunity to RHD2 as well. This vaccination requires a 9 monthly booster.
As part of Rabbit Awareness Week we are encouraging all rabbit owners to ensure that their rabbits are vaccinated against myxomatosis and BOTH strains of RHD. We are offering free health checks on the evening of 4th June 2019 with vets Ginny and Laura from 6.30pm. If your vaccinations have lapsed why not book in for our rabbit evening or book in with one of our other vets during the week to get them up to date and protected.