Introduced to control wild rabbit populations in Australia and Europe, myxomatosis causes prolonged suffering in wild rabbits, raising ongoing ethical questions about this widely used biological control.
Myxomatosis welfare harm is severe and intentional at its introduction but is now a permanent fixture of wild rabbit ecology in affected regions. Individual rabbits suffering from myxomatosis experience prolonged suffering — weeks of escalating debilitation before death. The scale of annual mortality is enormous. The ethical question of whether deliberately releasing a disease that causes prolonged suffering was justified by population control goals was debated at the time and remains relevant. The ongoing suffering is a welfare cost of historical control decisions that cannot be reversed.