Myxomatose

Myxomatosis, also known as myxomatosis, is a highly contagious viral disease of rabbits and some lagomorphs, caused by the myxoma virus, a large double-stranded DNA poxvirus in the genus Leporipoxvirus (family Poxviridae). The natural host is the European rabbit (Oryctolagus cuniculus); other lagomorph species show variable susceptibility. Transmission occurs mainly through direct contact with infected animals, and via ectoparasites such as mosquitoes and fleas (notably Spilopsyllus cuniculi), as well as fomites. Incubation is typically 5-14 days.

Clinically, the disease presents in several forms depending on viral virulence. The classical form begins with conjunctivitis, nasal discharge, swelling of the eyelids and face, and marked swelling of the lips and genitals; superficial, nodular lesions develop in the head and anogenital area, giving the name "myxomatous." Severe edema and secondary bacterial infections are common, and death can occur within 1-2 weeks in highly virulent outbreaks; less virulent strains may cause a longer illness with higher survival.

Diagnosis is based on clinical signs and can be confirmed by laboratory tests such as PCR or virus isolation. There is no antiviral cure; treatment is supportive and aims to prevent dehydration and secondary infections. Vaccination of domestic rabbits is available and recommended, and vector control and movement restrictions help prevent spread.

Historically, myxomatosis has had major ecological and economic impacts, including its use as a biological control agent in some regions, leading to selection for resistant rabbit populations and changing patterns of virulence over time.