I often hear in the media about certain diseases in animals, and honestly, I just donâ€™t tend to worry about them. For example, mad cow disease has only shown up in the US on two occasions, and those were both imported animals. So I donâ€™t really worry about mad cow disease. Another example is West Nile Virus. This disease is present in the United States. In fact a couple of instances have been found in southeast Michigan. Personally, I donâ€™t get real concerned about those things.
Myxomatosis is one of those diseases that I had some unfamiliarity with. In fact I thought it was limited to Europe and Australia. After doing some research I found that it is present in the United States and is a threat to both wild and domestic populations of rabbits. I wrote the first paragraph to tell you that I wonâ€™t panic or be stressed out over its existence. I will however, try to take some precautions to limit the risk to our rabbits.
Myxomatosis is a disease that is nearly always fatal. Nearly 99% of the rabbits that contract this virus will die. In Europe where a vaccination is available, vaccinated rabbits can still contract and will often die from this virus. It is highly contagious.
Myxomatosis is a viral infection. It is caused by a member of the Poxvirus family. The disease was first found in Uruguay in 1898 and it spread through South America and into Mexico. From Mexico the disease then made its way into California through infected domestic rabbits. Today the disease can be found primarily along the western coast of the US. This strain of the disease is called the California strain.
The myxoma virus has an ability to change slightly. It actual has natural mutations which makes each strain unique. In Australia the disease was purposely introduced into wild rabbits to control the rabbit population. Because of changes in the virus, and the rabbit populations developing resistance to the disease, mortality rates are now just 25% in the wild in Australia. However, domestic rabbits continue to have a much higher mortality rate.
Myxomatosis can be spread in a few different ways. The primary spread is done by infected insects carrying the virus. This is done primarily by mosquitoes and fleas. The insect bites an infected animal and then bites clean animal and causes its infection.
It is also believed that the disease can be spread through air. Basically, animals close enough to an infected animal can get this airborne virus. Research varies on how close the two animals must be. Some research claims they must be within a few feet of each other, while others claim it could possibly be up to a mile.
The final method of transmission is by contact. Either the infected animal comes in direct contact with a clean animal, or an owner touches an infected animal and then comes in contact with the uninfected animal without properly washing their hands.
Symptoms of this disease vary by both the strain of the disease contracted and the individual rabbits own immunities to the virus. Commonly the disease is signified by small lesions that appear 5 to 7 days after infection. Generally these legions, known as nodules, appear at the site of the bite, and then spread throughout the body. However, the California strain rarely has these lesions.
In the peracute form of the virus, there is high fever (often greater than 104), lack of appetite, lethargy, and swelling of the eyelids. Death will generally occur within 7-10 days of being infected, and usually within 48 hours of showing any signs of the disease.
Should the animal survive beyond the peracute stage it will enter the acute phase. The general sign at this stage is the swelling of the mucous membranes. This would include swelling in such areas as the nose, muzzle, genital area and anus. On occasion the entire face may actually swell. Rabbits that reach this stage will often die from hemorrhaging or seizures.
Prevention of myxomatosis is started by controlling insects near your rabbits. This would mean installing screens in doors and windows to prevent insects from entering your barn. Mechanical transmission can be prevented by quarantining any infected rabbit, and washing hands after contact. Any rabbit exposed to an infected rabbit should also be quarantined for 14 days.
It is always important that you know your rabbits. Handle them daily. Check them for signs of any illness, and immediately quarantine any rabbit you suspect may be ill, until you can be sure that they are fine, and your other rabbits are not at risk.