Myxomatosis is caused by a virus which is spread from rabbit to rabbit by blood-sucking insects, particularly the rabbit flea. It can spread from wild to domestic rabbits, but it does not affect any other animals such as hares, cats, dogs or humans. Infected individuals are recognised particularly by their swollen eyelids and ear bases. The disease was once invariable fatal, however, rabbits are now showing an ability to recover from infection.

When Myxomatosis first reached Britain in 1953, it spread rapidly and is estimated to have killed 99% of the wild rabbit population. Now weaker strains of the virus have come to predominate and in some areas rabbits have developed genetic resistance to the disease. In these ways the severity of the disease has been lessened so that by the 1980s it was only killing about 20% of the rabbits each year.

Outbreaks continue to occur locally however, often causing a higher level of mortality. It is, therefore, still a factor in keeping rabbit numbers below pre-myxomatosis levels in some areas, but it cannot be relied upon to reduce particular problem populations.

It is illegal to deliberately spread myxomatosis.

VHD A ‘new’ disease, Rabbit Viral Haemorrhagic Disease (VHD), has recently been recorded in the UK. Infected rabbits die within two to three days. Whilst this virus disease was initially thought to represent a similar threat to wild rabbits as Myxomatosis did in the 1950s, it has now been found that UK rabbits have some immunity to the disease. Local outbreaks can occur, but the disease does not appear to have the same effect on populations in the UK as it does in mainland Europe or Australasia.

Both of these diseases are extremely unpleasant and anybody who has seen an infected rabbit cannot help but feel pity for the animal.