Sheep link to bighorn illness adds to grazing controversy

Pneumonia is like the bird flu of the bighorn sheep world, and domestic sheep are prominent disease carriers. A recent study published by a Washington State University team confirmed what many already believed: domestic sheep, which aren’t as susceptible to M. haemolytica bacteria, transfer the bacteria when they come in contact with bighorn sheep, which then often die from it. The team modified bacteria to make them florescent, planted them in domestic sheep and then found the florescent bacteria in bighorns after they were allowed contact with domestic sheep. Wildlife managers knew bighorns tended to die from pneumonia after contacting domestic sheep, but some ranchers denied sheep were the cause. The study’s results provide more fuel for critics who argue that domestic sheep should not be allowed to graze on public lands where they could come into contact with bighorns. Pneumonia has surged recently. Bighorn sheep in neighboring states — Nevada, Utah, Wyoming, Montana and Washington — experienced severe losses last winter due to pneumonia. Francis Cassiser, a wildlife biologist with the Idaho Department of Fish and Game, said Idaho didn’t see the same sort of die-offs but didn’t know why...more