If you spend a lot of time outdoors, especially around lakes and other waterways, chances are you may run into a muskrat (a semi-aquatic rodent) at some point. It’s important to understand that muskrats do carry several diseases. Even though the chance of a healthy person contracting a disease from muskrats is minimal, common sense and caution are in order.
Muskrats most frequently carry the disease tularemia, caused by the bacteria Francisella tularensis. Muskrats contract the bacteria from infected ticks, flies and contaminated water. Humans get the disease by drinking contaminated water or touching infected animal tissue with an open wound. This typically occurs while skinning or gutting the animal, so wearing rubber gloves is advised, as well as washing hands after handling. While muskrats quickly succumb to the disease, it is not usually fatal to humans. Symptoms in people are flu-like and include fever, headache, joint and muscle pain and diarrhea. Most patients fully recover when the disease is treated with antibiotics.
Muskrats also carry leptospirosis, stemming from the Leptospira bacteria. Humans become infected with the bacteria when mucous membranes and broken skin come into contact with muskrat urine or other bodily fluids (except saliva). Drinking water contaminated by the bacteria is also a common route of leptospirosis transmission to humans. Infected people may be asymptomatic or experience a wide range of symptoms such as fever, chills, muscle aches, reddened eyes, diarrhea or vomiting, rash and abdominal pain. If left untreated, symptoms may initially subside but reoccur. The second phase of the illness, called Weil’s disease, is more severe and may result in kidney damage, meningitis, liver failure, difficulty breathing and occasionally death. Fortunately, treatment with antibiotics is available.
Muskrats are carriers of giardiasis, produced by Giardia intestinalis, a single-celled microscopic organism contained in a shell called a cyst. Humans contract giardiasis by drinking water contaminated with muskrat fecal matter containing the cysts. Experts at the United States Department of Agriculture Forest Service warn against drinking untreated water in the wilderness even if it appears clean, as giardiasis causes severe diarrhea and digestive discomfort.
Like all mammals, muskrats can carry the rabies virus, although the rate is quite low. According to the Centers for Disease Control and Prevention, only 1.8 percent of rabies cases involve rodents and lagomorphs (wild hares), compared to raccoons (36.5 percent), skunks (23.5 percent), bats (23.2 percent) and foxes (7 percent).
Caution and Common Sense
If you encounter a muskrat, stay away from the animal. Muskrats will do their best to avoid you, so common sense dictates that you do the same. If you handle live or dead muskrats, wear protective gloves or thoroughly wash hands after contact to help prevent any chance of disease.
A metropolitan Washington, D.C. resident, Bridget Cipollini has been writing professionally for more than 15 years. She received a Bachelor of Arts in journalism from Indiana University of Pennsylvania in 1986. She is a passionate advocate for animals and has volunteered for pet rescue and adoption organizations.