In Colorado, public health officials have announced that a squirrel has tested positive for the bubonic plague. The squirrel is the first case of the bubonic plague in the United States and was discovered in the town of Morrison, Colorado, in Jefferson County, which is just west of Denver.

“Plague is an infectious disease caused by the bacteria Yersinia pestis, and can be contracted by humans and household animals if proper precautions are not taken,” officials from Jefferson County Public Health (JCPH) said in a statement released to the public.

It is possible for humans to be infected with the bubonic plague through bites from infected fleas and by direct contact with blood or tissues of infected animals such as a cough or a bite. 

Jefferson County Public Health said that cats are highly susceptible to the plague from things like flea bites, a rodent scratch or bite, and ingesting an infected rodent. Cats can die if not treated quickly with antibiotics after contact with the plague.

Officials also said that dogs are not as susceptible to the plague as cats are but still may pick up and carry plague-infected rodent fleas. Officials warned that any pet owner who suspects that their pet is ill should contact a veterinarian immediately. 

“Symptoms of plague may include sudden onset of high fever, chills, headache, nausea and extreme pain and swelling of lymph nodes, occurring within two to seven days after exposure. Plague can be effectively treated with antibiotics when diagnosed early. Anyone experiencing these symptoms should consult a physician,” said JCPH.