Preventing Rabbit Myxomatosis

1 How It Spreads

Rabbits are the only susceptible animals; domestic and European rabbits are most at risk, with over 95% mortality, so the disease is essentially lethal. American cottontails and jackrabbits are the main reservoirs and carriers; they resist the virus and show only a few benign fibrous tumors at the bite site, but those tumors hold large amounts of virus, and insect bites are the chief means of spread.

Contact with sick rabbits or their contaminated feed, water, and tools can transmit the disease, but this is not the main route. Natural outbreaks mostly come from arthropods that bite a sick rabbit, carry the virus in their mouthparts, then infect healthy rabbits on the next bite. Aedes, Culex, and Anopheles mosquitoes, rabbit fleas, and stable flies are all potential vectors. Tests show the virus survives 105 days in rabbit fleas and can overwinter in mosquitoes.

In the Americas, Australia, and continental Europe, mosquitoes are the main vector; in Britain it is the rabbit flea, then mosquitoes. Because fleas are less seasonal, British myxomatosis shows no clear season.

2 Symptoms

Signs vary with viral strain and breed susceptibility. Meat rabbits show signs two days after infection: first conjunctivitis, then broad head swelling, with edema of the ears, nose, mouth, and jaw producing the ‘lion-head’ look, plus labored breathing, head shaking, sneezing, and rasping. Similar swelling appears around the anus and genitals. As it worsens, jelly-like tumors form under the edematous skin and the eyes discharge mucoid to purulent fluid; severe cases reach 42°C. Weaker strains cause milder, less raised tumors and lower death rates.

3 Prevention Measures

The disease is highly contagious and deadly and can devastate a rabbit operation. Trials show domestic rabbits in China have a 100% fatality rate, and although the country has seen no outbreaks, introduction would cause severe loss. Guard against it through biosecurity: strictly ban imports of breeding rabbits and rabbit products from affected countries, and quarantine all introduced stock to keep the virus out.