The Washington Department of Fish and Wildlife (WDFW) will begin this week to kill infected bighorn sheep in the Tieton herd about 10 miles west of Naches, Wash.
Pneumonia caused by Mycoplasma bacteria already has almost extirpated the herd from a high of about 200 sheep in recent years to the current estimate of 35 to 50 animals, said Richard Harris, the department's wildlife manager.
Biologists with WDFW and the U. S. Department of Agriculture's Wildlife Services will spend the next several weeks culling the sheep, and because most of the bighorns are believed to be infected with a disease, almost all of the animals will likely need to be killed, Harris said.
"A majority of the live bighorn sheep spotted during recent surveys looked to be in poor condition, with about a third of those animals coughing or showing other signs of the disease," Harris said. "We hate to have to take this action, but we believe it's necessary to stop the spread of a disease that could devastate adjacent herds of wild bighorn sheep in the area."
Past outbreaks among bighorn sheep in Washington and other parts of the western United States have been linked to contact between wild sheep and domestic sheep or goats that carry Mycoplasma but are unaffected by the bacteria. Harris said there is currently no evidence that there was contact between domestic and wild sheep in the Naches area.
In other news, bighorn sheep in Zion National Park have come down with sore mouth disease, a virus similar to chickenpox.
Reprinted in part from the Statesman Journal