Idaho officials say initial testing of dead rodents in southwest Idaho indicates possible plague.
The Idaho Department of Health and Welfare and the Idaho Department of Fish and Game in a statement Monday say dead voles have been found west of Caldwell.
Authorities say the dead voles appear to be in a localized area and not widespread.
Officials announced last month that ground squirrels south of Boise tested positive for plague, and advised humans and pets to avoid the area or take precautions.
The disease can be spread by flea bites or by direct contact with infected animals. The last two cases reported in Idaho, officials say, occurred in 1991 and 1992. Both patients fully recovered.
Authorities say avoiding contact with rodents will reduce the chance of becoming infected.