We have experienced a particularly wet summer this year and according to the Rabbit Welfare Association this has allowed the insects which can carry myxomatosis to flourish. Mosquitos and other biting insects do well in humid conditions, as do fleas. These insects may pass myxomatosis from one rabbit to another by biting an infected rabbit and then moving on to feed from another animal, hence transmitting the disease.
There seems to be an increased number of rabbits suffering with myxomatosis at the moment due to the increased numbers of insect carriers of the disease. Many of these infected rabbits will be put to sleep since it is generally a fatal disease and rabbits suffer greatly once the condition is apparent. Owners should look out for rabbits with swollen eyes, swollen genitals and breathing problems. If you notice any of these signs in your rabbit you should seek veterinary attention as soon as possible.
Myxomatosis can often be prevented if you have your rabbit vaccinated. The vaccine is not 100% effective but in my personal experience many vaccinated rabbits which go on to develop the disease were possibly infected before they received the vaccine. You should also try to prevent your rabbit having any contact with wild rabbits (they could have fleas which may be carrying the disease).
It is a good idea to get your pet rabbit vaccinated against myxomatosis. It is a nasty disease and causes a great deal of suffering. Most infected rabbits do not survive even with the best of veterinary care, so often these rabbits are euthanased as soon as the diagnosis is made. Not many pet rabbits are vaccinated for myxomatosis at the moment, but owners should definitely be considering it seriously this year.
Reference; Veterinary Record vol. 161, p 399