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Tularemia (rabbit fever, beaver fever)

Tularemia is also known as "beaver fever" or "rabbit fever". It is caused by a bacterium, Francisella tularensis. This bacterial disease is not common in Wisconsin but is most frequently found in Wisconsin muskrats, beaver, or rabbits.


The bacteria are typically transmitted to wildlife through the bites of ectoparasites such as mites, ticks, flies, midges, black flies, fleas, mosquitoes and lice.


There are generally very few signs associated with this disease in wildlife and they may only appear weak or slow-moving. Infected wild animals generally die quickly and will appear to be in good physical condition. They may have an enlarged spleen or liver covered with small white spots.


This disease is not common in Wisconsin wildlife. When it is confirmed, the removal of carcasses to reduce the risk to humans is recommended.


This disease can be transmitted to humans by biting insects, direct contact with infected animals, inhaling the bacteria during landscaping activities or eating contaminated meat or water. People should use insect repellents to avoid insect bites, avoid handling or mowing over dead wildlife and avoid drinking untreated water. Hunters should wear gloves when cleaning the game and cook game meat to the recommended temperature.