Rabbit myxomatosis

Rabbit myxomatosis is a highly contagious and fatal infectious disease caused by myxoma virus. It is characterized by myxomatous swelling under the skin of the whole body, especially on the face and around the natural pores. The OIE classifies it as a Class B disease.

1 Etiology

Myxoma virus is a member of the genus Lepoxvirus in the family Poxviridae.

The virus is resistant to desiccation and can survive for 2 weeks in dry myxoma nodules, more than 3 months in humid environments at 8~10℃, and 1~2 weeks at 26~30℃. It is sensitive to heat and is inactivated within 10 minutes at 55℃ and within a few minutes at 60℃. It has strong resistance to potassium permanganate, mercury chloride and carbolic acid. It takes 1 hour to inactivate the virus with O. 5%~2% formaldehyde solution.

2 Epidemiology

The infected rabbits were the source of infection, and the highest toxic content was found in the exudates of the infected rabbits 'eyes and skin. It is mainly transmitted by arthropod bites (most commonly mosquitoes and fleas). It can also be infected by direct contact with sick rabbits or contact with contaminated feed, drinking water and utensils.

This disease occurs only in rabbits and hares, other animals are not susceptible. It occurs mostly in summer and autumn when insects breed and reproduce.

3 Clinical symptoms

The incubation period is usually 3 to 7 days, up to 14 days.

It is characterized by generalized myxedema and subcutaneous peptone-like tumors. Primary tumor nodule at the site of venomous insect bite, followed by swollen eyelids, lacrimation, sticky or purulent eye dirt, severe upper and lower eyelids adhesion to each other. Swelling can spread throughout the subcutaneous tissue of the head and ears, giving the head skin a lion-head appearance. Swollen around anus, genitals, mouth and nostrils. Subcutaneous peptone-like tumor appeared in edema, especially at the junction of mucosa and skin.

4 Pathological changes

Prominent lesions are skin tumors, skin, subcutaneous edema, especially facial and natural holes around the skin obvious. Some strains can cause skin bleeding, gastric and intestinal serous congestion, intracardiac and epicardial bleeding, liver, spleen, kidney and lung congestion.

5 diagnostic

5.1 Preliminary diagnosis can be made according to typical clinical symptoms and pathological changes, and further laboratory diagnosis is required for diagnosis.

5.2 laboratory diagnosis

In international trade, there is no specific diagnostic method, alternative diagnostic methods are agar gel immunodiffusion test (AGID), complement fixation test (CF), indirect fluorescent antibody test (IFA).

Pathogen isolation and identification: immunodiffusion test (for dead rabbits with visible skin lesions), immunofluorescence test, or inoculation of rabbit kidney cells with diseased materials, and observation of cell lesions can also be identified.

Serological examination: complement fixation test, virus neutralization test, agar immunodiffusion test.

Sample collection: take pathological tissue, separate epidermis from dermis, wash with phosphate buffer for later use.

6 Prevention

Adopt general comprehensive epidemic prevention methods. When this disease occurs, the diseased rabbits and the same group of rabbits are culled and treated innocuously. Thoroughly disinfect contaminated environments, appliances, etc.