A ground squirrel (whistle pig) found south of Boise has tested positive for plague. Idaho public health officials and Idaho Fish and Game are asking people to take precautions as outdoor summer activities shift into high gear over the long Memorial Day weekend.
Plague is a bacterial disease of rodents that can cause serious illness to people and pets if not treated quickly. Plague is generally transmitted to humans and animals through the bites of infected fleas. It also can be transmitted by direct contact with infected animals, including rodents, rabbits and pets. Common rodents that can become infected include ground squirrels, rats and mice. Tree squirrels in Idaho are not known to carry plague.
“We have investigated reported mortalities of ground squirrels in the area southeast of Boise (see map below) during May,” State Wildlife Veterinarian Dr. Mark Drew said. “Dogs and cats can be infected with plague through hunting rodents, playing with or consuming their carcasses, or by exposure to their fleas.”
Plague activity can increase in the spring and summer months when rodents are more active. People can be exposed to plague when pets have contact with rodents or fleas outdoors, or bring infected rodents or fleas back into the home. People also can become infected by caring for a sick pet without proper precautions.
People can greatly reduce their risk of becoming infected with plague by taking simple precautions, including avoiding contact with wild rodents, their fleas and rodent carcasses. They should not feed rodents in picnic or campground areas and never handle sick or dead rodents. Health officials recommend:
- Keep your pets from roaming and hunting ground squirrels or other rodents in the desert south of Boise.
- Talk to your veterinarian about using an appropriate flea control product on pets as not all products are safe for cats, dogs or children.
- Clean up areas near your home where rodents can live, such as woodpiles.
- Sick pets should be examined promptly by a veterinarian, especially if they may have had contact with sick or dead rodents in the desert south of Boise
- See your doctor about any unexplained illness involving a sudden and severe fever.
- Put hay, wood, and compost piles as far as possible from your home.
- Don’t leave pet food and water where rodents or other wild animals can access them.
Symptoms of plague in humans include sudden onset of fever, chills, headache, and weakness. In most cases there is a painful swelling of the lymph node in the groin, armpit or neck areas. Plague symptoms in cats and dogs are fever, lethargy and loss of appetite. There may be a swelling in the lymph node under the jaw. With prompt diagnosis and appropriate antibiotic treatment, the fatality rate in people and pets can be greatly reduced. Physicians who suspect plague should promptly report it to their local public health district.
In Idaho, USDA Wildlife Services tested various species of carnivores between 2005 and 2010 for the presence of antibodies to plague and just 18 animals tested positive, primarily badgers and coyotes. If people find dead ground squirrels they should not touch them, but report the location through the Idaho Department of Fish and Game website.
Since 1940, only five human cases of plague have been reported in Idaho. The last two cases reported in Idaho occurred in 1991 and 1992, with both patients fully recovering.