July 1, 2025, 11:47 am | Read time: 4 minutes
It strikes suddenly, often progresses dramatically, and frequently ends fatally for unvaccinated animals: Myxomatosis is one of the most dangerous diseases affecting rabbits. But where does the risk lie, and what can owners do to protect their pets?
Myxomatosis, also known as rabbit plague, is a highly contagious viral disease primarily transmitted by mosquitoes. It often leads to severe symptoms and is usually fatal. Rabbits living in outdoor enclosures are particularly at risk. At the end of 2024, wild hares in Lower Saxony also died from a mutated variant of the virus for the first time, meaning that not only rabbits are now at risk.
Overview
The Myxomatosis Pathogen
The myxomatosis virus belongs to the poxvirus family. It exclusively infects rabbits, wild rabbits, and less frequently, wild hares. The latter usually suffer less severely from rabbit plague. Originally, the myxomatosis virus comes from South America. Native rabbit species, such as the cottontail rabbit, show little to no signs of illness. In the 1950s, a scientist had a strain of myxomatosis sent to his estate in France to control the out-of-control rabbit population on his land. However, the virus quickly spread throughout Europe, causing major epidemics among local rabbits.
At that time, the specific poxviruses were also introduced to Australia, and bait was laid out to curb the rabbit population. The rabbits, introduced by settlers, had become rampant in Australia due to a lack of natural predators and caused significant agricultural damage. To this day, infected bait is used in Australia to control overpopulations of wild rabbits.
Wild Hares in Germany Affected for the First Time
Myxomatosis is typically a viral disease that specifically affects rabbits. However, in the fall of 2024, numerous disoriented wild hares with inflamed eyes and swollen heads were discovered in Lower Saxony. This is the so-called Toledo variant of the virus, first confirmed in Spain in 2018. Once it appears, the virus remains in the populations. The disease re-emerged in April 2025. Estimating how many hares have already fallen victim to it in Germany is difficult, as Dr. Ulrich Voigt from the Institute for Terrestrial and Aquatic Wildlife Research at the University of Veterinary Medicine Hannover reports in an article in the hunting magazine “Pirsch.”
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Symptoms, Course, and Treatment
Rabbits infected with the myxomatosis virus show initial symptoms after a few days. They often appear apathetic and stop eating. Subsequently, the eyes usually become inflamed, and swelling occurs around the eyes, ears, and mouth. This swelling is often so severe that eating becomes nearly impossible and breathing is difficult. Untreated and unvaccinated animals often die 10 to 14 days after the onset of the disease.
If myxomatosis has already broken out, rabbits are usually treated with antibiotics to counteract inflammation in the head area. This also aims to prevent pneumonia. Eye drops and inhaling saline solution can also provide relief. Painkillers may also be used, as the severe swelling around the eyes and mouth can cause significant pain. Rabbits that have stopped eating should be fed. A needleless syringe can be used to administer pureed and pre-soaked rabbit food or baby fruit puree. The food should always be given in small portions to avoid overwhelming the sick animal’s digestive system.
To ease breathing through the swollen and clogged nose, baby nasal drops and regular cleaning with warm water and a soft washcloth can help. This also makes it easier to remove the crusts of the resulting pox after the symptoms subside. Once myxomatosis is overcome, these skin areas are usually bald, but the fur grows back in healthy rabbits.
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Infection and Prevention of Myxomatosis in Rabbits
Rabbits kept outdoors or partially outdoors are more frequently affected by myxomatosis than those kept exclusively indoors. This is because mosquitoes are the main transmitters of myxomatosis. Fleas and direct contact between rabbits can also facilitate transmission. Myxomatosis can also be transmitted if there is a large population of wild rabbits nearby and grass, hay, or dandelions from meadows and fields are fed to pets. The virus survives over 200 days in the environment. There are several ways to prevent infection:
- Isolation: New rabbits should be isolated for a period to detect any potential symptoms and prevent infection of other rabbits. At least 14 days of isolation is advisable.
- Food: Green food should only come from your own garden and only if no wild rabbits are present.
- Vaccination: There is a vaccine against myxomatosis. Administered by a veterinarian, it provides effective protection against a severe course of the disease but can only partially prevent infection. Most vaccinated rabbits survive myxomatosis, and the symptoms are less severe.