This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

MORRISON, Colo. (KDVR) – Health officials in Jefferson County have issued a warning to residents to be on alert for symptoms of bubonic plague.

On Saturday, a squirrel in Morrison tested positive for plague, which is caused by a bacteria called Yersinia pestis.

This is the first positive case of plague in the county this year, health officials said.

Plague can be spread to humans or other animals through direct contact, including bites, or through bites from infected fleas.

Jefferson County Public Health said cats are especially susceptible to plague and may die if not treated with antibiotics promptly. Dogs are at a lower risk but may pick up and carry infected fleas.

Symptoms of plague in humans 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. It can be effectively treated with antibiotics when diagnosed early.

Jefferson County Public Health (JCPH) recommends the following precautions be taken to protect yourself and your pets from plague. Risk for getting plague is extremely low as long as precautions are taken.

  • Eliminate all sources of food, shelter and access for wild animals around the home.
  • Do not feed wild animals.
  • Maintain a litter and trash-free yard to reduce wild animal habitats.
  • People and pets should avoid contact with sick or dead wild animals and rodents.
  • Use precaution when handling sick pets. Have sick pets examined by a veterinarian.
  • Consult with your veterinarian about flea and tick control for your pets.
  • Keep pets from roaming freely outside the home where they may prey on wild animals and bring the disease home with them.

To learn more about animal-borne diseases in Jefferson County, including plague, please visit