Myxamtosis and Rabbits June 2011
Myxomatosis is a particularly unpleasant killer disease of rabbits that we are seeing more frequently in both pet and wild rabbits this summer. Myxomatosis is caused by a virus and was originally introduced into the wild rabbit population to control numbers. Contrary to popular belief, myxomatosis is equally as dangerous to domesticated rabbits as to wild rabbits and even house rabbits are not completely safe.
The myxomatosis virus is spread from rabbit to rabbit by fleas and other blood sucking insects such as mosquitoes. Myxomatosis does not need direct rabbit to rabbit contact to spread widely in an area. Many animals can inadvertently carry infected rabbit fleas; for example, cats, dogs, hedgehogs and even humans. When the flea or mosquito bites a rabbit, it injects some of the virus into the skin and a new rabbit becomes infected.
The myxomatosis virus multiplies in the blood of the newly infected rabbit and, in 5 – 14 days, this rabbit is showing signs of the disease. The skin around the eyes, mouth, ears, genitalia and anus become puffy and the rabbit becomes poorly. The eyelids become so swollen that the rabbit cannot see and it has increasing difficulty in eating and drinking. There is slow progression of the disease and the rabbit usually dies in a couple of weeks.
There is no specific treatment for myxomatosis. There are a few reported cases of rabbits surviving with supportive care, antibiotics and good nursing; and the occasional wild rabbit will recover. Overall the out-look for a rabbit with myxomatosis is bleak and most owners opt for euthanasia on humane grounds.
There is a vaccination for myxomatosis that gives good (but not 100%) protection. It recommended that rabbits are vaccinated twice a year in high risk areas. Rabbits can be vaccinated from 6 weeks of age and it takes about two weeks for the rabbit to become immune. The vaccine rarely has any side-effects other than a small lump at the site of injection. Occasionally vaccinated rabbits may catch myxomatosis. In these cases, the disease is usually confined to skin lumps and fever. Most of these rabbits do recover but it can take some time.
Flea control is also important in controlling myxomatosis. There are a number of flea products available for rabbits. Where mosquitoes are a problem, netting may help reduce the risk of bites.
The myxomatosis virus may survive in fleas for the lifetime of the flea. It has been shown the virus survives winter in hibernating fleas. There is therefore a risk of a new (unvaccinated) rabbit catching myxomatosis if it is introduced to an area where a rabbit that has succumbed to myxomatosis lived before the fleas are eliminated. It is always advisable to have a rabbit vaccinated at least 2 weeks before introducing it to any area of high risk.
