myxómatosis

Myxomatosis is a highly contagious viral disease of rabbits caused by the myxoma virus, a member of the Leporipoxvirus genus in the Poxviridae family. It affects domestic rabbits and many wild species, often causing severe illness and high mortality. In many countries, vaccination is available to reduce risk in pet and farmed rabbits.

Transmission and pathogenesis: The virus spreads primarily through direct contact between infected and susceptible rabbits, but can also be transmitted by fomites and by biting insects such as fleas and mosquitoes. After entry, the virus replicates locally and disseminates through the body. Incubation is typically several days and disease severity depends on the virulence of the strain and the rabbit’s immune status. In highly virulent outbreaks, rabbits may deteriorate rapidly and die within days; milder strains can cause a longer course with more variable outcomes.

Clinical signs: Early signs include swelling of the eyelids and face, conjunctivitis, nasal discharge, and malaise. Cutaneous myxomas—gelatinous nodules—may develop on the head, genitalia, and limbs. Fever, lethargy, and loss of appetite are common, and secondary bacterial infections frequently occur. Death occurs in a substantial proportion of highly virulent infections, though some infections may be less fatal depending on strain and host factors.

Diagnosis and management: Diagnosis is based on history and clinical presentation, with confirmation by laboratory tests such as PCR or virus isolation. There is no specific antiviral treatment; care is supportive and may include antibiotics for secondary infections. Vaccination and vector control are key preventive measures.

Prevention and epidemiology: Domestic rabbits are commonly vaccinated where available. Quarantine of new animals, good hygiene, and control of insect vectors reduce spread. The disease has had notable ecological and economic impacts in regions where wild rabbit populations are a major component of the ecosystem or agriculture.