Myxomatosis is a severe, usually fatal viral disease in domestic and wild rabbits that can be largely prevented through vaccination, yet many pet rabbits remain unprotected.
Myxomatosis causes one of the most visibly distressing illnesses a pet owner can witness: the progressive facial swelling, conjunctivitis, and systemic illness unfold over days while the rabbit remains conscious and suffering. Early euthanasia is the most humane response once diagnosis is confirmed, but owners often delay hoping for recovery, extending suffering. The disease disproportionately affects owners who are unaware of vaccination requirements or cannot access veterinary care, and rabbits kept in outdoor enclosures face highest risk from insect vectors. Wild rabbit populations in Europe continue experiencing periodic mass mortality events from myxomatosis, representing a large-scale animal welfare and biodiversity concern. The lack of an approved vaccine in the USA leaves American pet rabbits without this protection entirely.