Myxomatosis
This disease is caused by a Myxoma virus that belongs to the family of pox viruses. The virus originates from South America where it causes a mild disease in the wild rabbit population. However when European rabbits were imported to South America the infection with the myxoma virus resulted in almost 100% mortality of the European rabbits. The European rabbit had been introduced to Australia by early colonists but by the 1950’s the rabbit population was out of control. In an attempt to reduce rabbit numbers the myxoma virus was intentionally introduced to Australia. By accident the virus was also introduced into Europe decimating the wild rabbit population.
The disease occurs in both domestic and wild rabbits but rarely in European hares that seem to have some resistance. The myxoma virus is spread by direct or indirect contact but most often by parasitic vectors. In Europe the rabbit flea and mosquito are the most important methods of spreading the virus. The virus can survive for several months in over wintering rabbit fleas and mosquitoes.
Symptoms
When the Myxoma virus originally infected unexposed European rabbits it produced an acute illness that resulted in 100% mortality. After infection, skin lesions appeared on the 3rd day and had spread every where by the 4th day. The skin lesions are typically swelling of the genitals and of the head, especially the eyelids which results in blindness. (See video below)The rabbit’s appetite remains normal until shortly before death which is on average 13 days after infection.
In time rabbits developed some immunity to the myxoma virus and the disease process changed in some cases to produce chronic form of Myxomatosis. In this chronic nodular form of Myxomatosis swellings called pseudotumours develop 10-15 days after infection. These lumps are mainly seen on the ears, nose and paws. The lumps or pseudotumours can spontaneously regress leaving scabs which later disappear. Mortality in the chronic nodular form is about 50% with an average survival time of 40days. Chronic Myxomatosis and Spirochaetosis (Rabbit Syphilis) can look very similar but spirochaetosis is extremely rare.
There are other forms of the disease that result in respiratory symptoms that can be very difficult to differentiate from other causes of pneumonia such as pasturellae.
Please Donate for the up keep of this website,
Many Thanks Wiltshire Rabbit Control