Myxomatosis is a viral disease spread by fleas and mosquitoes and recently we have witnessed an increased incidence locally in pet rabbits. Weather conditions may affect the populations of the vector or carrier insect, increasing the numbers of mosquitoes and fleas in warm humid climates.
In this country myxomatosis typically occurs in the late Autumn, and early Winter months, as we are currently witnessing. The virus can live in the rabbit flea for several months and probably over winters in wild rabbit burrows-hence reappearing year after year.
Once bitten by an infected flea or mosquito the virus is introduced into the rabbits circulation and may take 5-14 days to cause clinical signs of disease. It is not spread from direct contact with other rabbits – it only spreads via the flea or mosquito.
Historically the disease was introduced into Australia in 1950, destroying the wild rabbit populations and was accidentally introduced into Europe by a French bacteriologist in 1952, interested in reducing rabbits on his estate. Rabbits poached from the estate were blamed for the introduction of the disease into the rest of France and Europe.
By 1953 the disease had reached UK and the situation was worsened by deliberate spreading of disease by people placing affected rabbits into burrows to facilitate the virus spread.
Signs of disease are initially the presence of swellings of the eyelids, nose and genitals, rapidly followed by conjunctivitis and vision difficulties; secondary bacterial infections then develop, often causing pneumonia. Initially rabbits affected become listless and inappetance follows.
Although it is possible to nurse rabbits during the disease, death generally occurs within a 10-14 day period, and euthanasia is often the kindest treatment for pet rabbits infected.
Pet owners can reduce the chances of disease by using insecticides on their rabbits routinely to reduce the chances of being bitten by mosquitoes and fleas, and the use of fly screens/ nets to protect the hutch may help.
Ensuring the bedding is dry reduces attraction to insect vectors. Prevention of contact with wild rabbit populations is sensible.
However, vaccination proves to be the most effective method of prevention, and annual vaccinations to maintain immunity are essential. Vaccination can be carried out from 6 weeks of age and affords protection within 2 weeks and vaccine manufacturers suggest 6 monthly repeat vaccination if local incidence of disease is high.