LAS VEGAS (AP) - Wildlife biologists say a bacterial pneumonia outbreak appears to have spread from bighorn sheep herds in the River Mountains between Henderson and Boulder City to sheep in three other ranges.
Nevada Department of Wildlife biologist Pat Cummings on Wednesday called the discovery of diseased bighorn in the Eldorado, McCullough and Spring mountains a "worst-case scenario."
The Las Vegas Review-Journal reports (http://bit.ly/1nQwshv) that the spread of the illness complicates efforts to restore bighorn to ranges throughout Nevada and the West.
Officials say the illness poses no risk to humans, but there is no treatment or vaccination for the bighorn.
Wildlife officials don't know for sure how many sheep have died or will die.
But they say bighorn have no natural resistance to pneumonia and tend to succumb at a high rate.