Myxomatosis is a viral disease of rabbits caused by myxoma virus. It was released into the wild rabbit population in an attempt at population control, and is now widespread.
Infection can be passed on by direct contact, but it is more often spread by biting insects – mainly rabbit fleas but also mosquitoes and other biting flies.
Infected rabbits have a high fever and are listless and anorexic. The most obvious clinical sign is a severe conjunctivitis and ocular discharge. Some rabbits will die during this acute phase of infection. Those that survive this phase develop marked swelling of the mouth, eyelids, nostrils and genitalia. This is rapidly followed by severe respiratory infection, coma and death.
The mortality rate from myxomatosis is extremely high, and there is unfortunately no effective treatment. Affected rabbits almost always have to be euthanased to relieve them of the suffering the illness causes.
Vaccination against myxomatosis is the best way to prevent disease. Occasionally a vaccinated rabbit will still be infected with the virus, but they generally remain well and demonstrate only a small amount of facial swelling. They then go on to make a full recovery.
In addition, protecting your rabbit against fleas will help to lower the risk of myxomatosis transmission, but we would not advise relying on this alone.