A beaver in Glacier National Park tested positive for a rare but serious zoonotic disease known as tularemia.

While most commonly associated with hares, rabbits and rodents, the bacterial infection has been documented in dozens of species, including humans. The Centers for Disease Control and Prevention documented 196 cases of tularemia in 2023 — the last year for which data is available — including two cases in Montana.  

Tularemia is highly infectious with multiple ways to spread. Ticks, mosquitos and other blood-sucking bugs act as vectors for the disease, carrying the bacteria from one animal to another. People can also contract tularemia by drinking contaminated water, inhaling contaminated dust or directly handling an infected animal.  

Human-to-human transmission is not known to occur. 

Symptoms in humans typically develop between a few days and two weeks of exposure and include fever, swollen lymph nodes, chills, nausea and vomiting, muscle aches and abdominal pain.  

When diagnosed early, tularemia is treatable with antibiotics. Human fatality rates vary from less than 2% to 24%, depending on the route of infection and the degree of medical treatment received. 

The infected beaver was discovered between Upper and Lower St. Mary Lakes on the eastern side of the park. Officials are advising anyone that develops symptoms of tularemia after visiting the area to seek medical attention and inform their healthcare provider of a possible exposure to the bacteria. 

Park visitors can reduce their risk by applying insect repellent, keeping a safe distance from all wildlife and drinking only treated water.  

Glacier National Park officials did not provide an immediate response to a list of questions, including whether the infected beaver was dead or alive, whether it displayed any symptoms of tularemia and whether the park would conduct any further sampling for the disease. 

Reporter Hailey Smalley can be reached at 406-758-4433 or [email protected]. If you value local journalism, pledge your support at dailyinterlake.com/support.